/* Copyright (C) 1995-2002 MySQL AB This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; version 2 of the License. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ /** @file This file contains the implementation of prepared statements. When one prepares a statement: - Server gets the query from client with command 'COM_STMT_PREPARE'; in the following format: [COM_STMT_PREPARE:1] [query] - Parse the query and recognize any parameter markers '?' and store its information list in lex->param_list - Allocate a new statement for this prepare; and keep this in 'thd->stmt_map'. - Without executing the query, return back to client the total number of parameters along with result-set metadata information (if any) in the following format: @verbatim [STMT_ID:4] [Column_count:2] [Param_count:2] [Params meta info (stubs only for now)] (if Param_count > 0) [Columns meta info] (if Column_count > 0) @endverbatim During prepare the tables used in a statement are opened, but no locks are acquired. Table opening will block any DDL during the operation, and we do not need any locks as we neither read nor modify any data during prepare. Tables are closed after prepare finishes. When one executes a statement: - Server gets the command 'COM_STMT_EXECUTE' to execute the previously prepared query. If there are any parameter markers, then the client will send the data in the following format: @verbatim [COM_STMT_EXECUTE:1] [STMT_ID:4] [NULL_BITS:(param_count+7)/8)] [TYPES_SUPPLIED_BY_CLIENT(0/1):1] [[length]data] [[length]data] .. [[length]data]. @endverbatim (Note: Except for string/binary types; all other types will not be supplied with length field) - If it is a first execute or types of parameters were altered by client, then setup the conversion routines. - Assign parameter items from the supplied data. - Execute the query without re-parsing and send back the results to client During execution of prepared statement tables are opened and locked the same way they would for normal (non-prepared) statement execution. Tables are unlocked and closed after the execution. When one supplies long data for a placeholder: - Server gets the long data in pieces with command type 'COM_STMT_SEND_LONG_DATA'. - The packet recieved will have the format as: [COM_STMT_SEND_LONG_DATA:1][STMT_ID:4][parameter_number:2][data] - data from the packet is appended to the long data value buffer for this placeholder. - It's up to the client to stop supplying data chunks at any point. The server doesn't care; also, the server doesn't notify the client whether it got the data or not; if there is any error, then it will be returned at statement execute. */ #include "mysql_priv.h" #include "sql_select.h" // for JOIN #include "sql_cursor.h" #include "sp_head.h" #include "sp.h" #include "sp_cache.h" #ifdef EMBEDDED_LIBRARY /* include MYSQL_BIND headers */ #include <mysql.h> #else #include <mysql_com.h> #endif /** A result class used to send cursor rows using the binary protocol. */ class Select_fetch_protocol_binary: public select_send { Protocol_binary protocol; public: Select_fetch_protocol_binary(THD *thd); virtual bool send_fields(List<Item> &list, uint flags); virtual bool send_data(List<Item> &items); virtual bool send_eof(); #ifdef EMBEDDED_LIBRARY void begin_dataset() { protocol.begin_dataset(); } #endif }; /****************************************************************************/ /** Prepared_statement: a statement that can contain placeholders. */ class Prepared_statement: public Statement { public: enum flag_values { IS_IN_USE= 1 }; THD *thd; Select_fetch_protocol_binary result; Protocol *protocol; Item_param **param_array; uint param_count; uint last_errno; uint flags; char last_error[MYSQL_ERRMSG_SIZE]; #ifndef EMBEDDED_LIBRARY bool (*set_params)(Prepared_statement *st, uchar *data, uchar *data_end, uchar *read_pos, String *expanded_query); #else bool (*set_params_data)(Prepared_statement *st, String *expanded_query); #endif bool (*set_params_from_vars)(Prepared_statement *stmt, List<LEX_STRING>& varnames, String *expanded_query); public: Prepared_statement(THD *thd_arg, Protocol *protocol_arg); virtual ~Prepared_statement(); void setup_set_params(); virtual Query_arena::Type type() const; virtual void cleanup_stmt(); bool set_name(LEX_STRING *name); inline void close_cursor() { delete cursor; cursor= 0; } bool prepare(const char *packet, uint packet_length); bool execute(String *expanded_query, bool open_cursor); /* Destroy this statement */ bool deallocate(); private: /** Store the parsed tree of a prepared statement here. */ LEX main_lex; /** The memory root to allocate parsed tree elements (instances of Item, SELECT_LEX and other classes). */ MEM_ROOT main_mem_root; }; /****************************************************************************** Implementation ******************************************************************************/ inline bool is_param_null(const uchar *pos, ulong param_no) { return pos[param_no/8] & (1 << (param_no & 7)); } /** Find a prepared statement in the statement map by id. Try to find a prepared statement and set THD error if it's not found. @param thd thread handle @param id statement id @param where the place from which this function is called (for error reporting). @return 0 if the statement was not found, a pointer otherwise. */ static Prepared_statement * find_prepared_statement(THD *thd, ulong id, const char *where) { /* To strictly separate namespaces of SQL prepared statements and C API prepared statements find() will return 0 if there is a named prepared statement with such id. */ Statement *stmt= thd->stmt_map.find(id); if (stmt == 0 || stmt->type() != Query_arena::PREPARED_STATEMENT) { char llbuf[22]; my_error(ER_UNKNOWN_STMT_HANDLER, MYF(0), sizeof(llbuf), llstr(id, llbuf), where); return 0; } return (Prepared_statement *) stmt; } /** Send prepared statement id and metadata to the client after prepare. @todo Fix this nasty upcast from List<Item_param> to List<Item> @return 0 in case of success, 1 otherwise */ #ifndef EMBEDDED_LIBRARY static bool send_prep_stmt(Prepared_statement *stmt, uint columns) { NET *net= &stmt->thd->net; uchar buff[12]; uint tmp; DBUG_ENTER("send_prep_stmt"); buff[0]= 0; /* OK packet indicator */ int4store(buff+1, stmt->id); int2store(buff+5, columns); int2store(buff+7, stmt->param_count); buff[9]= 0; // Guard against a 4.1 client tmp= min(stmt->thd->total_warn_count, 65535); int2store(buff+10, tmp); /* Send types and names of placeholders to the client XXX: fix this nasty upcast from List<Item_param> to List<Item> */ DBUG_RETURN(my_net_write(net, buff, sizeof(buff)) || (stmt->param_count && stmt->thd->protocol_text.send_fields((List<Item> *) &stmt->lex->param_list, Protocol::SEND_EOF))); } #else static bool send_prep_stmt(Prepared_statement *stmt, uint columns __attribute__((unused))) { THD *thd= stmt->thd; thd->client_stmt_id= stmt->id; thd->client_param_count= stmt->param_count; thd->clear_error(); return 0; } #endif /*!EMBEDDED_LIBRARY*/ #ifndef EMBEDDED_LIBRARY /** Read the length of the parameter data and return it back to the caller. Read data length, position the packet to the first byte after it, and return the length to the caller. @param packet a pointer to the data @param len remaining packet length @return Length of data piece. */ static ulong get_param_length(uchar **packet, ulong len) { reg1 uchar *pos= *packet; if (len < 1) return 0; if (*pos < 251) { (*packet)++; return (ulong) *pos; } if (len < 3) return 0; if (*pos == 252) { (*packet)+=3; return (ulong) uint2korr(pos+1); } if (len < 4) return 0; if (*pos == 253) { (*packet)+=4; return (ulong) uint3korr(pos+1); } if (len < 5) return 0; (*packet)+=9; // Must be 254 when here /* In our client-server protocol all numbers bigger than 2^24 stored as 8 bytes with uint8korr. Here we always know that parameter length is less than 2^4 so don't look at the second 4 bytes. But still we need to obey the protocol hence 9 in the assignment above. */ return (ulong) uint4korr(pos+1); } #else #define get_param_length(packet, len) len #endif /*!EMBEDDED_LIBRARY*/ /** Data conversion routines. All these functions read the data from pos, convert it to requested type and assign to param; pos is advanced to predefined length. Make a note that the NULL handling is examined at first execution (i.e. when input types altered) and for all subsequent executions we don't read any values for this. @param param parameter item @param pos input data buffer @param len length of data in the buffer */ static void set_param_tiny(Item_param *param, uchar **pos, ulong len) { #ifndef EMBEDDED_LIBRARY if (len < 1) return; #endif int8 value= (int8) **pos; param->set_int(param->unsigned_flag ? (longlong) ((uint8) value) : (longlong) value, 4); *pos+= 1; } static void set_param_short(Item_param *param, uchar **pos, ulong len) { int16 value; #ifndef EMBEDDED_LIBRARY if (len < 2) return; value= sint2korr(*pos); #else shortget(value, *pos); #endif param->set_int(param->unsigned_flag ? (longlong) ((uint16) value) : (longlong) value, 6); *pos+= 2; } static void set_param_int32(Item_param *param, uchar **pos, ulong len) { int32 value; #ifndef EMBEDDED_LIBRARY if (len < 4) return; value= sint4korr(*pos); #else longget(value, *pos); #endif param->set_int(param->unsigned_flag ? (longlong) ((uint32) value) : (longlong) value, 11); *pos+= 4; } static void set_param_int64(Item_param *param, uchar **pos, ulong len) { longlong value; #ifndef EMBEDDED_LIBRARY if (len < 8) return; value= (longlong) sint8korr(*pos); #else longlongget(value, *pos); #endif param->set_int(value, 21); *pos+= 8; } static void set_param_float(Item_param *param, uchar **pos, ulong len) { float data; #ifndef EMBEDDED_LIBRARY if (len < 4) return; float4get(data,*pos); #else floatget(data, *pos); #endif param->set_double((double) data); *pos+= 4; } static void set_param_double(Item_param *param, uchar **pos, ulong len) { double data; #ifndef EMBEDDED_LIBRARY if (len < 8) return; float8get(data,*pos); #else doubleget(data, *pos); #endif param->set_double((double) data); *pos+= 8; } static void set_param_decimal(Item_param *param, uchar **pos, ulong len) { ulong length= get_param_length(pos, len); param->set_decimal((char*)*pos, length); *pos+= length; } #ifndef EMBEDDED_LIBRARY /* Read date/time/datetime parameter values from network (binary protocol). See writing counterparts of these functions in libmysql.c (store_param_{time,date,datetime}). */ /** @todo Add warning 'Data truncated' here */ static void set_param_time(Item_param *param, uchar **pos, ulong len) { MYSQL_TIME tm; ulong length= get_param_length(pos, len); if (length >= 8) { uchar *to= *pos; uint day; tm.neg= (bool) to[0]; day= (uint) sint4korr(to+1); tm.hour= (uint) to[5] + day * 24; tm.minute= (uint) to[6]; tm.second= (uint) to[7]; tm.second_part= (length > 8) ? (ulong) sint4korr(to+8) : 0; if (tm.hour > 838) { /* TODO: add warning 'Data truncated' here */ tm.hour= 838; tm.minute= 59; tm.second= 59; } tm.day= tm.year= tm.month= 0; } else set_zero_time(&tm, MYSQL_TIMESTAMP_TIME); param->set_time(&tm, MYSQL_TIMESTAMP_TIME, MAX_TIME_WIDTH * MY_CHARSET_BIN_MB_MAXLEN); *pos+= length; } static void set_param_datetime(Item_param *param, uchar **pos, ulong len) { MYSQL_TIME tm; ulong length= get_param_length(pos, len); if (length >= 4) { uchar *to= *pos; tm.neg= 0; tm.year= (uint) sint2korr(to); tm.month= (uint) to[2]; tm.day= (uint) to[3]; if (length > 4) { tm.hour= (uint) to[4]; tm.minute= (uint) to[5]; tm.second= (uint) to[6]; } else tm.hour= tm.minute= tm.second= 0; tm.second_part= (length > 7) ? (ulong) sint4korr(to+7) : 0; } else set_zero_time(&tm, MYSQL_TIMESTAMP_DATETIME); param->set_time(&tm, MYSQL_TIMESTAMP_DATETIME, MAX_DATETIME_WIDTH * MY_CHARSET_BIN_MB_MAXLEN); *pos+= length; } static void set_param_date(Item_param *param, uchar **pos, ulong len) { MYSQL_TIME tm; ulong length= get_param_length(pos, len); if (length >= 4) { uchar *to= *pos; tm.year= (uint) sint2korr(to); tm.month= (uint) to[2]; tm.day= (uint) to[3]; tm.hour= tm.minute= tm.second= 0; tm.second_part= 0; tm.neg= 0; } else set_zero_time(&tm, MYSQL_TIMESTAMP_DATE); param->set_time(&tm, MYSQL_TIMESTAMP_DATE, MAX_DATE_WIDTH * MY_CHARSET_BIN_MB_MAXLEN); *pos+= length; } #else/*!EMBEDDED_LIBRARY*/ /** @todo Add warning 'Data truncated' here */ void set_param_time(Item_param *param, uchar **pos, ulong len) { MYSQL_TIME tm= *((MYSQL_TIME*)*pos); tm.hour+= tm.day * 24; tm.day= tm.year= tm.month= 0; if (tm.hour > 838) { /* TODO: add warning 'Data truncated' here */ tm.hour= 838; tm.minute= 59; tm.second= 59; } param->set_time(&tm, MYSQL_TIMESTAMP_TIME, MAX_TIME_WIDTH * MY_CHARSET_BIN_MB_MAXLEN); } void set_param_datetime(Item_param *param, uchar **pos, ulong len) { MYSQL_TIME tm= *((MYSQL_TIME*)*pos); tm.neg= 0; param->set_time(&tm, MYSQL_TIMESTAMP_DATETIME, MAX_DATETIME_WIDTH * MY_CHARSET_BIN_MB_MAXLEN); } void set_param_date(Item_param *param, uchar **pos, ulong len) { MYSQL_TIME *to= (MYSQL_TIME*)*pos; param->set_time(to, MYSQL_TIMESTAMP_DATE, MAX_DATE_WIDTH * MY_CHARSET_BIN_MB_MAXLEN); } #endif /*!EMBEDDED_LIBRARY*/ static void set_param_str(Item_param *param, uchar **pos, ulong len) { ulong length= get_param_length(pos, len); if (length > len) length= len; param->set_str((const char *)*pos, length); *pos+= length; } #undef get_param_length static void setup_one_conversion_function(THD *thd, Item_param *param, uchar param_type) { switch (param_type) { case MYSQL_TYPE_TINY: param->set_param_func= set_param_tiny; param->item_type= Item::INT_ITEM; param->item_result_type= INT_RESULT; break; case MYSQL_TYPE_SHORT: param->set_param_func= set_param_short; param->item_type= Item::INT_ITEM; param->item_result_type= INT_RESULT; break; case MYSQL_TYPE_LONG: param->set_param_func= set_param_int32; param->item_type= Item::INT_ITEM; param->item_result_type= INT_RESULT; break; case MYSQL_TYPE_LONGLONG: param->set_param_func= set_param_int64; param->item_type= Item::INT_ITEM; param->item_result_type= INT_RESULT; break; case MYSQL_TYPE_FLOAT: param->set_param_func= set_param_float; param->item_type= Item::REAL_ITEM; param->item_result_type= REAL_RESULT; break; case MYSQL_TYPE_DOUBLE: param->set_param_func= set_param_double; param->item_type= Item::REAL_ITEM; param->item_result_type= REAL_RESULT; break; case MYSQL_TYPE_DECIMAL: case MYSQL_TYPE_NEWDECIMAL: param->set_param_func= set_param_decimal; param->item_type= Item::DECIMAL_ITEM; param->item_result_type= DECIMAL_RESULT; break; case MYSQL_TYPE_TIME: param->set_param_func= set_param_time; param->item_type= Item::STRING_ITEM; param->item_result_type= STRING_RESULT; break; case MYSQL_TYPE_DATE: param->set_param_func= set_param_date; param->item_type= Item::STRING_ITEM; param->item_result_type= STRING_RESULT; break; case MYSQL_TYPE_DATETIME: case MYSQL_TYPE_TIMESTAMP: param->set_param_func= set_param_datetime; param->item_type= Item::STRING_ITEM; param->item_result_type= STRING_RESULT; break; case MYSQL_TYPE_TINY_BLOB: case MYSQL_TYPE_MEDIUM_BLOB: case MYSQL_TYPE_LONG_BLOB: case MYSQL_TYPE_BLOB: param->set_param_func= set_param_str; param->value.cs_info.character_set_of_placeholder= &my_charset_bin; param->value.cs_info.character_set_client= thd->variables.character_set_client; DBUG_ASSERT(thd->variables.character_set_client); param->value.cs_info.final_character_set_of_str_value= &my_charset_bin; param->item_type= Item::STRING_ITEM; param->item_result_type= STRING_RESULT; break; default: /* The client library ensures that we won't get any other typecodes except typecodes above and typecodes for string types. Marking label as 'default' lets us to handle malformed packets as well. */ { CHARSET_INFO *fromcs= thd->variables.character_set_client; CHARSET_INFO *tocs= thd->variables.collation_connection; uint32 dummy_offset; param->value.cs_info.character_set_of_placeholder= fromcs; param->value.cs_info.character_set_client= fromcs; /* Setup source and destination character sets so that they are different only if conversion is necessary: this will make later checks easier. */ param->value.cs_info.final_character_set_of_str_value= String::needs_conversion(0, fromcs, tocs, &dummy_offset) ? tocs : fromcs; param->set_param_func= set_param_str; /* Exact value of max_length is not known unless data is converted to charset of connection, so we have to set it later. */ param->item_type= Item::STRING_ITEM; param->item_result_type= STRING_RESULT; } } param->param_type= (enum enum_field_types) param_type; } #ifndef EMBEDDED_LIBRARY /** Routines to assign parameters from data supplied by the client. Update the parameter markers by reading data from the packet and and generate a valid query for logging. @note This function, along with other _with_log functions is called when one of binary, slow or general logs is open. Logging of prepared statements in all cases is performed by means of conventional queries: if parameter data was supplied from C API, each placeholder in the query is replaced with its actual value; if we're logging a [Dynamic] SQL prepared statement, parameter markers are replaced with variable names. Example: @verbatim mysql_stmt_prepare("UPDATE t1 SET a=a*1.25 WHERE a=?") --> general logs gets [Prepare] UPDATE t1 SET a*1.25 WHERE a=?" mysql_stmt_execute(stmt); --> general and binary logs get [Execute] UPDATE t1 SET a*1.25 WHERE a=1" @endverbatim If a statement has been prepared using SQL syntax: @verbatim PREPARE stmt FROM "UPDATE t1 SET a=a*1.25 WHERE a=?" --> general log gets [Query] PREPARE stmt FROM "UPDATE ..." EXECUTE stmt USING @a --> general log gets [Query] EXECUTE stmt USING @a; @endverbatim @retval 0 if success @retval 1 otherwise */ static bool insert_params_with_log(Prepared_statement *stmt, uchar *null_array, uchar *read_pos, uchar *data_end, String *query) { THD *thd= stmt->thd; Item_param **begin= stmt->param_array; Item_param **end= begin + stmt->param_count; uint32 length= 0; String str; const String *res; DBUG_ENTER("insert_params_with_log"); if (query->copy(stmt->query, stmt->query_length, default_charset_info)) DBUG_RETURN(1); for (Item_param **it= begin; it < end; ++it) { Item_param *param= *it; if (param->state != Item_param::LONG_DATA_VALUE) { if (is_param_null(null_array, it - begin)) param->set_null(); else { if (read_pos >= data_end) DBUG_RETURN(1); param->set_param_func(param, &read_pos, data_end - read_pos); if (param->state == Item_param::NO_VALUE) DBUG_RETURN(1); } } res= param->query_val_str(&str); if (param->convert_str_value(thd)) DBUG_RETURN(1); /* out of memory */ if (query->replace(param->pos_in_query+length, 1, *res)) DBUG_RETURN(1); length+= res->length()-1; } DBUG_RETURN(0); } static bool insert_params(Prepared_statement *stmt, uchar *null_array, uchar *read_pos, uchar *data_end, String *expanded_query) { Item_param **begin= stmt->param_array; Item_param **end= begin + stmt->param_count; DBUG_ENTER("insert_params"); for (Item_param **it= begin; it < end; ++it) { Item_param *param= *it; if (param->state != Item_param::LONG_DATA_VALUE) { if (is_param_null(null_array, it - begin)) param->set_null(); else { if (read_pos >= data_end) DBUG_RETURN(1); param->set_param_func(param, &read_pos, data_end - read_pos); if (param->state == Item_param::NO_VALUE) DBUG_RETURN(1); } } if (param->convert_str_value(stmt->thd)) DBUG_RETURN(1); /* out of memory */ } DBUG_RETURN(0); } static bool setup_conversion_functions(Prepared_statement *stmt, uchar **data, uchar *data_end) { /* skip null bits */ uchar *read_pos= *data + (stmt->param_count+7) / 8; DBUG_ENTER("setup_conversion_functions"); if (*read_pos++) //types supplied / first execute { /* First execute or types altered by the client, setup the conversion routines for all parameters (one time) */ Item_param **it= stmt->param_array; Item_param **end= it + stmt->param_count; THD *thd= stmt->thd; for (; it < end; ++it) { ushort typecode; const uint signed_bit= 1 << 15; if (read_pos >= data_end) DBUG_RETURN(1); typecode= sint2korr(read_pos); read_pos+= 2; (**it).unsigned_flag= test(typecode & signed_bit); setup_one_conversion_function(thd, *it, (uchar) (typecode & ~signed_bit)); } } *data= read_pos; DBUG_RETURN(0); } #else /** Embedded counterparts of parameter assignment routines. The main difference between the embedded library and the server is that in embedded case we don't serialize/deserialize parameters data. Additionally, for unknown reason, the client-side flag raised for changed types of placeholders is ignored and we simply setup conversion functions at each execute (TODO: fix). */ static bool emb_insert_params(Prepared_statement *stmt, String *expanded_query) { THD *thd= stmt->thd; Item_param **it= stmt->param_array; Item_param **end= it + stmt->param_count; MYSQL_BIND *client_param= stmt->thd->client_params; DBUG_ENTER("emb_insert_params"); for (; it < end; ++it, ++client_param) { Item_param *param= *it; setup_one_conversion_function(thd, param, client_param->buffer_type); if (param->state != Item_param::LONG_DATA_VALUE) { if (*client_param->is_null) param->set_null(); else { uchar *buff= (uchar*) client_param->buffer; param->unsigned_flag= client_param->is_unsigned; param->set_param_func(param, &buff, client_param->length ? *client_param->length : client_param->buffer_length); if (param->state == Item_param::NO_VALUE) DBUG_RETURN(1); } } if (param->convert_str_value(thd)) DBUG_RETURN(1); /* out of memory */ } DBUG_RETURN(0); } static bool emb_insert_params_with_log(Prepared_statement *stmt, String *query) { THD *thd= stmt->thd; Item_param **it= stmt->param_array; Item_param **end= it + stmt->param_count; MYSQL_BIND *client_param= thd->client_params; String str; const String *res; uint32 length= 0; DBUG_ENTER("emb_insert_params_with_log"); if (query->copy(stmt->query, stmt->query_length, default_charset_info)) DBUG_RETURN(1); for (; it < end; ++it, ++client_param) { Item_param *param= *it; setup_one_conversion_function(thd, param, client_param->buffer_type); if (param->state != Item_param::LONG_DATA_VALUE) { if (*client_param->is_null) param->set_null(); else { uchar *buff= (uchar*)client_param->buffer; param->unsigned_flag= client_param->is_unsigned; param->set_param_func(param, &buff, client_param->length ? *client_param->length : client_param->buffer_length); if (param->state == Item_param::NO_VALUE) DBUG_RETURN(1); } } res= param->query_val_str(&str); if (param->convert_str_value(thd)) DBUG_RETURN(1); /* out of memory */ if (query->replace(param->pos_in_query+length, 1, *res)) DBUG_RETURN(1); length+= res->length()-1; } DBUG_RETURN(0); } #endif /*!EMBEDDED_LIBRARY*/ /** Assign prepared statement parameters from user variables. @param stmt Statement @param varnames List of variables. Caller must ensure that number of variables in the list is equal to number of statement parameters @param query Ignored */ static bool insert_params_from_vars(Prepared_statement *stmt, List<LEX_STRING>& varnames, String *query __attribute__((unused))) { Item_param **begin= stmt->param_array; Item_param **end= begin + stmt->param_count; user_var_entry *entry; LEX_STRING *varname; List_iterator<LEX_STRING> var_it(varnames); DBUG_ENTER("insert_params_from_vars"); for (Item_param **it= begin; it < end; ++it) { Item_param *param= *it; varname= var_it++; entry= (user_var_entry*)hash_search(&stmt->thd->user_vars, (uchar*) varname->str, varname->length); if (param->set_from_user_var(stmt->thd, entry) || param->convert_str_value(stmt->thd)) DBUG_RETURN(1); } DBUG_RETURN(0); } /** Do the same as insert_params_from_vars but also construct query text for binary log. @param stmt Prepared statement @param varnames List of variables. Caller must ensure that number of variables in the list is equal to number of statement parameters @param query The query with parameter markers replaced with corresponding user variables that were used to execute the query. */ static bool insert_params_from_vars_with_log(Prepared_statement *stmt, List<LEX_STRING>& varnames, String *query) { Item_param **begin= stmt->param_array; Item_param **end= begin + stmt->param_count; user_var_entry *entry; LEX_STRING *varname; List_iterator<LEX_STRING> var_it(varnames); String buf; const String *val; uint32 length= 0; THD *thd= stmt->thd; DBUG_ENTER("insert_params_from_vars"); if (query->copy(stmt->query, stmt->query_length, default_charset_info)) DBUG_RETURN(1); for (Item_param **it= begin; it < end; ++it) { Item_param *param= *it; varname= var_it++; entry= (user_var_entry *) hash_search(&thd->user_vars, (uchar*) varname->str, varname->length); /* We have to call the setup_one_conversion_function() here to set the parameter's members that might be needed further (e.g. value.cs_info.character_set_client is used in the query_val_str()). */ setup_one_conversion_function(thd, param, param->param_type); if (param->set_from_user_var(thd, entry)) DBUG_RETURN(1); val= param->query_val_str(&buf); if (param->convert_str_value(thd)) DBUG_RETURN(1); /* out of memory */ if (query->replace(param->pos_in_query+length, 1, *val)) DBUG_RETURN(1); length+= val->length()-1; } DBUG_RETURN(0); } /** Validate INSERT statement. @param stmt prepared statement @param tables global/local table list @retval FALSE success @retval TRUE error, error message is set in THD */ static bool mysql_test_insert(Prepared_statement *stmt, TABLE_LIST *table_list, List<Item> &fields, List<List_item> &values_list, List<Item> &update_fields, List<Item> &update_values, enum_duplicates duplic) { THD *thd= stmt->thd; List_iterator_fast<List_item> its(values_list); List_item *values; DBUG_ENTER("mysql_test_insert"); if (insert_precheck(thd, table_list)) goto error; /* open temporary memory pool for temporary data allocated by derived tables & preparation procedure Note that this is done without locks (should not be needed as we will not access any data here) If we would use locks, then we have to ensure we are not using TL_WRITE_DELAYED as having two such locks can cause table corruption. */ if (open_normal_and_derived_tables(thd, table_list, 0)) goto error; if ((values= its++)) { uint value_count; ulong counter= 0; Item *unused_conds= 0; if (table_list->table) { // don't allocate insert_values table_list->table->insert_values=(uchar *)1; } if (mysql_prepare_insert(thd, table_list, table_list->table, fields, values, update_fields, update_values, duplic, &unused_conds, FALSE, FALSE, FALSE)) goto error; value_count= values->elements; its.rewind(); if (table_list->lock_type == TL_WRITE_DELAYED && !(table_list->table->file->ha_table_flags() & HA_CAN_INSERT_DELAYED)) { my_error(ER_ILLEGAL_HA, MYF(0), (table_list->view ? table_list->view_name.str : table_list->table_name)); goto error; } while ((values= its++)) { counter++; if (values->elements != value_count) { my_error(ER_WRONG_VALUE_COUNT_ON_ROW, MYF(0), counter); goto error; } if (setup_fields(thd, 0, *values, MARK_COLUMNS_NONE, 0, 0)) goto error; } } DBUG_RETURN(FALSE); error: /* insert_values is cleared in open_table */ DBUG_RETURN(TRUE); } /** Validate UPDATE statement. @param stmt prepared statement @param tables list of tables used in this query @todo - here we should send types of placeholders to the client. @retval 0 success @retval 1 error, error message is set in THD @retval 2 convert to multi_update */ static int mysql_test_update(Prepared_statement *stmt, TABLE_LIST *table_list) { int res; THD *thd= stmt->thd; uint table_count= 0; SELECT_LEX *select= &stmt->lex->select_lex; #ifndef NO_EMBEDDED_ACCESS_CHECKS uint want_privilege; #endif DBUG_ENTER("mysql_test_update"); if (update_precheck(thd, table_list) || open_tables(thd, &table_list, &table_count, 0)) goto error; if (table_list->multitable_view) { DBUG_ASSERT(table_list->view != 0); DBUG_PRINT("info", ("Switch to multi-update")); /* pass counter value */ thd->lex->table_count= table_count; /* convert to multiupdate */ DBUG_RETURN(2); } /* thd->fill_derived_tables() is false here for sure (because it is preparation of PS, so we even do not check it). */ if (mysql_handle_derived(thd->lex, &mysql_derived_prepare)) goto error; #ifndef NO_EMBEDDED_ACCESS_CHECKS /* Force privilege re-checking for views after they have been opened. */ want_privilege= (table_list->view ? UPDATE_ACL : table_list->grant.want_privilege); #endif if (mysql_prepare_update(thd, table_list, &select->where, select->order_list.elements, (ORDER *) select->order_list.first)) goto error; #ifndef NO_EMBEDDED_ACCESS_CHECKS table_list->grant.want_privilege= want_privilege; table_list->table->grant.want_privilege= want_privilege; table_list->register_want_access(want_privilege); #endif thd->lex->select_lex.no_wrap_view_item= TRUE; res= setup_fields(thd, 0, select->item_list, MARK_COLUMNS_READ, 0, 0); thd->lex->select_lex.no_wrap_view_item= FALSE; if (res) goto error; #ifndef NO_EMBEDDED_ACCESS_CHECKS /* Check values */ table_list->grant.want_privilege= table_list->table->grant.want_privilege= (SELECT_ACL & ~table_list->table->grant.privilege); table_list->register_want_access(SELECT_ACL); #endif if (setup_fields(thd, 0, stmt->lex->value_list, MARK_COLUMNS_NONE, 0, 0)) goto error; /* TODO: here we should send types of placeholders to the client. */ DBUG_RETURN(0); error: DBUG_RETURN(1); } /** Validate DELETE statement. @param stmt prepared statement @param tables list of tables used in this query @retval FALSE success @retval TRUE error, error message is set in THD */ static bool mysql_test_delete(Prepared_statement *stmt, TABLE_LIST *table_list) { THD *thd= stmt->thd; LEX *lex= stmt->lex; DBUG_ENTER("mysql_test_delete"); if (delete_precheck(thd, table_list) || open_normal_and_derived_tables(thd, table_list, 0)) goto error; if (!table_list->table) { my_error(ER_VIEW_DELETE_MERGE_VIEW, MYF(0), table_list->view_db.str, table_list->view_name.str); goto error; } DBUG_RETURN(mysql_prepare_delete(thd, table_list, &lex->select_lex.where)); error: DBUG_RETURN(TRUE); } /** Validate SELECT statement. In case of success, if this query is not EXPLAIN, send column list info back to the client. @param stmt prepared statement @param tables list of tables used in the query @retval 0 success @retval 1 error, error message is set in THD @retval 2 success, and statement metadata has been sent */ static int mysql_test_select(Prepared_statement *stmt, TABLE_LIST *tables, bool text_protocol) { THD *thd= stmt->thd; LEX *lex= stmt->lex; SELECT_LEX_UNIT *unit= &lex->unit; DBUG_ENTER("mysql_test_select"); lex->select_lex.context.resolve_in_select_list= TRUE; ulong privilege= lex->exchange ? SELECT_ACL | FILE_ACL : SELECT_ACL; if (tables) { if (check_table_access(thd, privilege, tables,0)) goto error; } else if (check_access(thd, privilege, any_db,0,0,0,0)) goto error; if (!lex->result && !(lex->result= new (stmt->mem_root) select_send)) { my_error(ER_OUTOFMEMORY, MYF(0), sizeof(select_send)); goto error; } if (open_normal_and_derived_tables(thd, tables, 0)) goto error; thd->used_tables= 0; // Updated by setup_fields /* JOIN::prepare calls It is not SELECT COMMAND for sure, so setup_tables will be called as usual, and we pass 0 as setup_tables_done_option */ if (unit->prepare(thd, 0, 0)) goto error; if (!lex->describe && !text_protocol) { /* Make copy of item list, as change_columns may change it */ List<Item> fields(lex->select_lex.item_list); /* Change columns if a procedure like analyse() */ if (unit->last_procedure && unit->last_procedure->change_columns(fields)) goto error; /* We can use lex->result as it should've been prepared in unit->prepare call above. */ if (send_prep_stmt(stmt, lex->result->field_count(fields)) || lex->result->send_fields(fields, Protocol::SEND_EOF) || thd->protocol->flush()) goto error; DBUG_RETURN(2); } DBUG_RETURN(0); error: DBUG_RETURN(1); } /** Validate and prepare for execution DO statement expressions. @param stmt prepared statement @param tables list of tables used in this query @param values list of expressions @retval FALSE success @retval TRUE error, error message is set in THD */ static bool mysql_test_do_fields(Prepared_statement *stmt, TABLE_LIST *tables, List<Item> *values) { THD *thd= stmt->thd; DBUG_ENTER("mysql_test_do_fields"); if (tables && check_table_access(thd, SELECT_ACL, tables, 0)) DBUG_RETURN(TRUE); if (open_normal_and_derived_tables(thd, tables, 0)) DBUG_RETURN(TRUE); DBUG_RETURN(setup_fields(thd, 0, *values, MARK_COLUMNS_NONE, 0, 0)); } /** Validate and prepare for execution SET statement expressions. @param stmt prepared statement @param tables list of tables used in this query @param values list of expressions @retval FALSE success @retval TRUE error, error message is set in THD */ static bool mysql_test_set_fields(Prepared_statement *stmt, TABLE_LIST *tables, List<set_var_base> *var_list) { DBUG_ENTER("mysql_test_set_fields"); List_iterator_fast<set_var_base> it(*var_list); THD *thd= stmt->thd; set_var_base *var; if (tables && check_table_access(thd, SELECT_ACL, tables, 0) || open_normal_and_derived_tables(thd, tables, 0)) goto error; while ((var= it++)) { if (var->light_check(thd)) goto error; } DBUG_RETURN(FALSE); error: DBUG_RETURN(TRUE); } /** Check internal SELECT of the prepared command. @param stmt prepared statement @param specific_prepare function of command specific prepare @param setup_tables_done_option options to be passed to LEX::unit.prepare() @note This function won't directly open tables used in select. They should be opened either by calling function (and in this case you probably should use select_like_stmt_test_with_open()) or by "specific_prepare" call (like this happens in case of multi-update). @retval FALSE success @retval TRUE error, error message is set in THD */ static bool select_like_stmt_test(Prepared_statement *stmt, bool (*specific_prepare)(THD *thd), ulong setup_tables_done_option) { DBUG_ENTER("select_like_stmt_test"); THD *thd= stmt->thd; LEX *lex= stmt->lex; lex->select_lex.context.resolve_in_select_list= TRUE; if (specific_prepare && (*specific_prepare)(thd)) DBUG_RETURN(TRUE); thd->used_tables= 0; // Updated by setup_fields /* Calls JOIN::prepare */ DBUG_RETURN(lex->unit.prepare(thd, 0, setup_tables_done_option)); } /** Check internal SELECT of the prepared command (with opening of used tables). @param stmt prepared statement @param tables list of tables to be opened before calling specific_prepare function @param specific_prepare function of command specific prepare @param setup_tables_done_option options to be passed to LEX::unit.prepare() @retval FALSE success @retval TRUE error */ static bool select_like_stmt_test_with_open(Prepared_statement *stmt, TABLE_LIST *tables, bool (*specific_prepare)(THD *thd), ulong setup_tables_done_option) { DBUG_ENTER("select_like_stmt_test_with_open"); /* We should not call LEX::unit.cleanup() after this open_normal_and_derived_tables() call because we don't allow prepared EXPLAIN yet so derived tables will clean up after themself. */ if (open_normal_and_derived_tables(stmt->thd, tables, 0)) DBUG_RETURN(TRUE); DBUG_RETURN(select_like_stmt_test(stmt, specific_prepare, setup_tables_done_option)); } /** Validate and prepare for execution CREATE TABLE statement. @param stmt prepared statement @param tables list of tables used in this query @retval FALSE success @retval TRUE error, error message is set in THD */ static bool mysql_test_create_table(Prepared_statement *stmt) { DBUG_ENTER("mysql_test_create_table"); THD *thd= stmt->thd; LEX *lex= stmt->lex; SELECT_LEX *select_lex= &lex->select_lex; bool res= FALSE; /* Skip first table, which is the table we are creating */ bool link_to_local; TABLE_LIST *create_table= lex->unlink_first_table(&link_to_local); TABLE_LIST *tables= lex->query_tables; if (create_table_precheck(thd, tables, create_table)) DBUG_RETURN(TRUE); if (select_lex->item_list.elements) { if (!(lex->create_info.options & HA_LEX_CREATE_TMP_TABLE)) { lex->link_first_table_back(create_table, link_to_local); create_table->create= TRUE; } if (open_normal_and_derived_tables(stmt->thd, lex->query_tables, 0)) DBUG_RETURN(TRUE); if (!(lex->create_info.options & HA_LEX_CREATE_TMP_TABLE)) create_table= lex->unlink_first_table(&link_to_local); select_lex->context.resolve_in_select_list= TRUE; res= select_like_stmt_test(stmt, 0, 0); } /* put tables back for PS rexecuting */ lex->link_first_table_back(create_table, link_to_local); DBUG_RETURN(res); } /** Validate and prepare for execution a multi update statement. @param stmt prepared statement @param tables list of tables used in this query @param converted converted to multi-update from usual update @retval FALSE success @retval TRUE error, error message is set in THD */ static bool mysql_test_multiupdate(Prepared_statement *stmt, TABLE_LIST *tables, bool converted) { /* if we switched from normal update, rights are checked */ if (!converted && multi_update_precheck(stmt->thd, tables)) return TRUE; return select_like_stmt_test(stmt, &mysql_multi_update_prepare, OPTION_SETUP_TABLES_DONE); } /** Validate and prepare for execution a multi delete statement. @param stmt prepared statement @param tables list of tables used in this query @retval FALSE success @retval TRUE error, error message in THD is set. */ static bool mysql_test_multidelete(Prepared_statement *stmt, TABLE_LIST *tables) { stmt->thd->lex->current_select= &stmt->thd->lex->select_lex; if (add_item_to_list(stmt->thd, new Item_null())) { my_error(ER_OUTOFMEMORY, MYF(0), 0); goto error; } if (multi_delete_precheck(stmt->thd, tables) || select_like_stmt_test_with_open(stmt, tables, &mysql_multi_delete_prepare, OPTION_SETUP_TABLES_DONE)) goto error; if (!tables->table) { my_error(ER_VIEW_DELETE_MERGE_VIEW, MYF(0), tables->view_db.str, tables->view_name.str); goto error; } return FALSE; error: return TRUE; } /** Wrapper for mysql_insert_select_prepare, to make change of local tables after open_normal_and_derived_tables() call. @param thd thread handle @note We need to remove the first local table after open_normal_and_derived_tables(), because mysql_handle_derived uses local tables lists. */ static bool mysql_insert_select_prepare_tester(THD *thd) { SELECT_LEX *first_select= &thd->lex->select_lex; TABLE_LIST *second_table= ((TABLE_LIST*)first_select->table_list.first)-> next_local; /* Skip first table, which is the table we are inserting in */ first_select->table_list.first= (uchar *) second_table; thd->lex->select_lex.context.table_list= thd->lex->select_lex.context.first_name_resolution_table= second_table; return mysql_insert_select_prepare(thd); } /** Validate and prepare for execution INSERT ... SELECT statement. @param stmt prepared statement @param tables list of tables used in this query @retval FALSE success @retval TRUE error, error message is set in THD */ static bool mysql_test_insert_select(Prepared_statement *stmt, TABLE_LIST *tables) { int res; LEX *lex= stmt->lex; TABLE_LIST *first_local_table; if (tables->table) { // don't allocate insert_values tables->table->insert_values=(uchar *)1; } if (insert_precheck(stmt->thd, tables)) return 1; /* store it, because mysql_insert_select_prepare_tester change it */ first_local_table= (TABLE_LIST *)lex->select_lex.table_list.first; DBUG_ASSERT(first_local_table != 0); res= select_like_stmt_test_with_open(stmt, tables, &mysql_insert_select_prepare_tester, OPTION_SETUP_TABLES_DONE); /* revert changes made by mysql_insert_select_prepare_tester */ lex->select_lex.table_list.first= (uchar*) first_local_table; return res; } /** Perform semantic analysis of the parsed tree and send a response packet to the client. This function - opens all tables and checks access rights - validates semantics of statement columns and SQL functions by calling fix_fields. @param stmt prepared statement @retval FALSE success, statement metadata is sent to client @retval TRUE error, error message is set in THD (but not sent) */ static bool check_prepared_statement(Prepared_statement *stmt, bool text_protocol) { THD *thd= stmt->thd; LEX *lex= stmt->lex; SELECT_LEX *select_lex= &lex->select_lex; TABLE_LIST *tables; enum enum_sql_command sql_command= lex->sql_command; int res= 0; DBUG_ENTER("check_prepared_statement"); DBUG_PRINT("enter",("command: %d param_count: %u", sql_command, stmt->param_count)); lex->first_lists_tables_same(); tables= lex->query_tables; /* set context for commands which do not use setup_tables */ lex->select_lex.context.resolve_in_table_list_only(select_lex-> get_table_list()); switch (sql_command) { case SQLCOM_REPLACE: case SQLCOM_INSERT: res= mysql_test_insert(stmt, tables, lex->field_list, lex->many_values, lex->update_list, lex->value_list, lex->duplicates); break; case SQLCOM_UPDATE: res= mysql_test_update(stmt, tables); /* mysql_test_update returns 2 if we need to switch to multi-update */ if (res != 2) break; case SQLCOM_UPDATE_MULTI: res= mysql_test_multiupdate(stmt, tables, res == 2); break; case SQLCOM_DELETE: res= mysql_test_delete(stmt, tables); break; case SQLCOM_SELECT: res= mysql_test_select(stmt, tables, text_protocol); if (res == 2) { /* Statement and field info has already been sent */ DBUG_RETURN(FALSE); } break; case SQLCOM_CREATE_TABLE: res= mysql_test_create_table(stmt); break; case SQLCOM_CREATE_VIEW: if (lex->create_view_mode == VIEW_ALTER) { my_message(ER_UNSUPPORTED_PS, ER(ER_UNSUPPORTED_PS), MYF(0)); goto error; } break; case SQLCOM_DO: res= mysql_test_do_fields(stmt, tables, lex->insert_list); break; case SQLCOM_SET_OPTION: res= mysql_test_set_fields(stmt, tables, &lex->var_list); break; case SQLCOM_DELETE_MULTI: res= mysql_test_multidelete(stmt, tables); break; case SQLCOM_INSERT_SELECT: case SQLCOM_REPLACE_SELECT: res= mysql_test_insert_select(stmt, tables); break; /* Note that we don't need to have cases in this list if they are marked with CF_STATUS_COMMAND in sql_command_flags */ case SQLCOM_SHOW_PROCESSLIST: case SQLCOM_SHOW_STORAGE_ENGINES: case SQLCOM_SHOW_PRIVILEGES: case SQLCOM_SHOW_COLUMN_TYPES: case SQLCOM_SHOW_ENGINE_LOGS: case SQLCOM_SHOW_ENGINE_STATUS: case SQLCOM_SHOW_ENGINE_MUTEX: case SQLCOM_SHOW_CREATE_DB: case SQLCOM_SHOW_GRANTS: case SQLCOM_SHOW_BINLOG_EVENTS: case SQLCOM_SHOW_MASTER_STAT: case SQLCOM_SHOW_SLAVE_STAT: case SQLCOM_SHOW_CREATE_PROC: case SQLCOM_SHOW_CREATE_FUNC: case SQLCOM_SHOW_CREATE_EVENT: case SQLCOM_SHOW_CREATE_TRIGGER: case SQLCOM_SHOW_CREATE: case SQLCOM_SHOW_PROC_CODE: case SQLCOM_SHOW_FUNC_CODE: case SQLCOM_SHOW_AUTHORS: case SQLCOM_SHOW_CONTRIBUTORS: case SQLCOM_SHOW_WARNS: case SQLCOM_SHOW_ERRORS: case SQLCOM_SHOW_BINLOGS: case SQLCOM_DROP_TABLE: case SQLCOM_RENAME_TABLE: case SQLCOM_ALTER_TABLE: case SQLCOM_COMMIT: case SQLCOM_CREATE_INDEX: case SQLCOM_DROP_INDEX: case SQLCOM_ROLLBACK: case SQLCOM_TRUNCATE: case SQLCOM_CALL: case SQLCOM_DROP_VIEW: case SQLCOM_REPAIR: case SQLCOM_ANALYZE: case SQLCOM_OPTIMIZE: case SQLCOM_CHANGE_MASTER: case SQLCOM_RESET: case SQLCOM_FLUSH: case SQLCOM_SLAVE_START: case SQLCOM_SLAVE_STOP: case SQLCOM_INSTALL_PLUGIN: case SQLCOM_UNINSTALL_PLUGIN: case SQLCOM_CREATE_DB: case SQLCOM_DROP_DB: case SQLCOM_ALTER_DB_UPGRADE: case SQLCOM_CHECKSUM: case SQLCOM_CREATE_USER: case SQLCOM_RENAME_USER: case SQLCOM_DROP_USER: case SQLCOM_ASSIGN_TO_KEYCACHE: case SQLCOM_PRELOAD_KEYS: case SQLCOM_GRANT: case SQLCOM_REVOKE: case SQLCOM_KILL: break; case SQLCOM_PREPARE: case SQLCOM_EXECUTE: case SQLCOM_DEALLOCATE_PREPARE: default: /* Trivial check of all status commands. This is easier than having things in the above case list, as it's less chance for mistakes. */ if (!(sql_command_flags[sql_command] & CF_STATUS_COMMAND)) { /* All other statements are not supported yet. */ my_message(ER_UNSUPPORTED_PS, ER(ER_UNSUPPORTED_PS), MYF(0)); goto error; } break; } if (res == 0) DBUG_RETURN(text_protocol? FALSE : (send_prep_stmt(stmt, 0) || thd->protocol->flush())); error: DBUG_RETURN(TRUE); } /** Initialize array of parameters in statement from LEX. (We need to have quick access to items by number in mysql_stmt_get_longdata). This is to avoid using malloc/realloc in the parser. */ static bool init_param_array(Prepared_statement *stmt) { LEX *lex= stmt->lex; if ((stmt->param_count= lex->param_list.elements)) { if (stmt->param_count > (uint) UINT_MAX16) { /* Error code to be defined in 5.0 */ my_message(ER_PS_MANY_PARAM, ER(ER_PS_MANY_PARAM), MYF(0)); return TRUE; } Item_param **to; List_iterator<Item_param> param_iterator(lex->param_list); /* Use thd->mem_root as it points at statement mem_root */ stmt->param_array= (Item_param **) alloc_root(stmt->thd->mem_root, sizeof(Item_param*) * stmt->param_count); if (!stmt->param_array) return TRUE; for (to= stmt->param_array; to < stmt->param_array + stmt->param_count; ++to) { *to= param_iterator++; } } return FALSE; } /** COM_STMT_PREPARE handler. Given a query string with parameter markers, create a prepared statement from it and send PS info back to the client. If parameter markers are found in the query, then store the information using Item_param along with maintaining a list in lex->param_array, so that a fast and direct retrieval can be made without going through all field items. @param packet query to be prepared @param packet_length query string length, including ignored trailing NULL or quote char. @note This function parses the query and sends the total number of parameters and resultset metadata information back to client (if any), without executing the query i.e. without any log/disk writes. This allows the queries to be re-executed without re-parsing during execute. @return none: in case of success a new statement id and metadata is sent to the client, otherwise an error message is set in THD. */ void mysql_stmt_prepare(THD *thd, const char *packet, uint packet_length) { Prepared_statement *stmt; bool error; DBUG_ENTER("mysql_stmt_prepare"); DBUG_PRINT("prep_query", ("%s", packet)); /* First of all clear possible warnings from the previous command */ mysql_reset_thd_for_next_command(thd); if (! (stmt= new Prepared_statement(thd, &thd->protocol_binary))) DBUG_VOID_RETURN; /* out of memory: error is set in Sql_alloc */ if (thd->stmt_map.insert(thd, stmt)) { /* The error is set in the insert. The statement itself will be also deleted there (this is how the hash works). */ DBUG_VOID_RETURN; } /* Reset warnings from previous command */ mysql_reset_errors(thd, 0); sp_cache_flush_obsolete(&thd->sp_proc_cache); sp_cache_flush_obsolete(&thd->sp_func_cache); if (!(specialflag & SPECIAL_NO_PRIOR)) my_pthread_setprio(pthread_self(),QUERY_PRIOR); error= stmt->prepare(packet, packet_length); if (!(specialflag & SPECIAL_NO_PRIOR)) my_pthread_setprio(pthread_self(),WAIT_PRIOR); if (error) { /* Statement map deletes statement on erase */ thd->stmt_map.erase(stmt); } /* check_prepared_statemnt sends the metadata packet in case of success */ DBUG_VOID_RETURN; } /** Get an SQL statement text from a user variable or from plain text. If the statement is plain text, just assign the pointers, otherwise allocate memory in thd->mem_root and copy the contents of the variable, possibly with character set conversion. @param[in] lex main lex @param[out] query_len length of the SQL statement (is set only in case of success) @retval non-zero success @retval 0 in case of error (out of memory) */ static const char *get_dynamic_sql_string(LEX *lex, uint *query_len) { THD *thd= lex->thd; char *query_str= 0; if (lex->prepared_stmt_code_is_varref) { /* This is PREPARE stmt FROM or EXECUTE IMMEDIATE @var. */ String str; CHARSET_INFO *to_cs= thd->variables.collation_connection; bool needs_conversion; user_var_entry *entry; String *var_value= &str; uint32 unused, len; /* Convert @var contents to string in connection character set. Although it is known that int/real/NULL value cannot be a valid query we still convert it for error messages to be uniform. */ if ((entry= (user_var_entry*)hash_search(&thd->user_vars, (uchar*)lex->prepared_stmt_code.str, lex->prepared_stmt_code.length)) && entry->value) { my_bool is_var_null; var_value= entry->val_str(&is_var_null, &str, NOT_FIXED_DEC); /* NULL value of variable checked early as entry->value so here we can't get NULL in normal conditions */ DBUG_ASSERT(!is_var_null); if (!var_value) goto end; } else { /* variable absent or equal to NULL, so we need to set variable to something reasonable to get a readable error message during parsing */ str.set(STRING_WITH_LEN("NULL"), &my_charset_latin1); } needs_conversion= String::needs_conversion(var_value->length(), var_value->charset(), to_cs, &unused); len= (needs_conversion ? var_value->length() * to_cs->mbmaxlen : var_value->length()); if (!(query_str= (char*) alloc_root(thd->mem_root, len+1))) goto end; if (needs_conversion) { uint dummy_errors; len= copy_and_convert(query_str, len, to_cs, var_value->ptr(), var_value->length(), var_value->charset(), &dummy_errors); } else memcpy(query_str, var_value->ptr(), var_value->length()); query_str[len]= '\0'; // Safety (mostly for debug) *query_len= len; } else { query_str= lex->prepared_stmt_code.str; *query_len= lex->prepared_stmt_code.length; } end: return query_str; } /** Init PS/SP specific parse tree members. */ static void init_stmt_after_parse(LEX *lex) { SELECT_LEX *sl= lex->all_selects_list; /* Switch off a temporary flag that prevents evaluation of subqueries in statement prepare. */ for (; sl; sl= sl->next_select_in_list()) sl->uncacheable&= ~UNCACHEABLE_PREPARE; } /** SQLCOM_PREPARE implementation. Prepare an SQL prepared statement. This is called from mysql_execute_command and should therefore behave like an ordinary query (e.g. should not reset any global THD data). @param thd thread handle @return none: in case of success, OK packet is sent to the client, otherwise an error message is set in THD */ void mysql_sql_stmt_prepare(THD *thd) { LEX *lex= thd->lex; LEX_STRING *name= &lex->prepared_stmt_name; Prepared_statement *stmt; const char *query; uint query_len; DBUG_ENTER("mysql_sql_stmt_prepare"); LINT_INIT(query_len); DBUG_ASSERT(thd->protocol == &thd->protocol_text); if ((stmt= (Prepared_statement*) thd->stmt_map.find_by_name(name))) { /* If there is a statement with the same name, remove it. It is ok to remove old and fail to insert a new one at the same time. */ if (stmt->deallocate()) DBUG_VOID_RETURN; } if (! (query= get_dynamic_sql_string(lex, &query_len)) || ! (stmt= new Prepared_statement(thd, &thd->protocol_text))) { DBUG_VOID_RETURN; /* out of memory */ } /* Set the name first, insert should know that this statement has a name */ if (stmt->set_name(name)) { delete stmt; DBUG_VOID_RETURN; } if (thd->stmt_map.insert(thd, stmt)) { /* The statement is deleted and an error is set if insert fails */ DBUG_VOID_RETURN; } if (stmt->prepare(query, query_len)) { /* Statement map deletes the statement on erase */ thd->stmt_map.erase(stmt); } else send_ok(thd, 0L, 0L, "Statement prepared"); DBUG_VOID_RETURN; } /** Reinit prepared statement/stored procedure before execution. @todo When the new table structure is ready, then have a status bit to indicate the table is altered, and re-do the setup_* and open the tables back. */ void reinit_stmt_before_use(THD *thd, LEX *lex) { SELECT_LEX *sl= lex->all_selects_list; DBUG_ENTER("reinit_stmt_before_use"); /* We have to update "thd" pointer in LEX, all its units and in LEX::result, since statements which belong to trigger body are associated with TABLE object and because of this can be used in different threads. */ lex->thd= thd; if (lex->empty_field_list_on_rset) { lex->empty_field_list_on_rset= 0; lex->field_list.empty(); } for (; sl; sl= sl->next_select_in_list()) { if (!sl->first_execution) { /* remove option which was put by mysql_explain_union() */ sl->options&= ~SELECT_DESCRIBE; /* see unique_table() */ sl->exclude_from_table_unique_test= FALSE; /* Copy WHERE, HAVING clause pointers to avoid damaging them by optimisation */ if (sl->prep_where) { sl->where= sl->prep_where->copy_andor_structure(thd); sl->where->cleanup(); } if (sl->prep_having) { sl->having= sl->prep_having->copy_andor_structure(thd); sl->having->cleanup(); } DBUG_ASSERT(sl->join == 0); ORDER *order; /* Fix GROUP list */ for (order= (ORDER *)sl->group_list.first; order; order= order->next) order->item= &order->item_ptr; /* Fix ORDER list */ for (order= (ORDER *)sl->order_list.first; order; order= order->next) order->item= &order->item_ptr; } { SELECT_LEX_UNIT *unit= sl->master_unit(); unit->unclean(); unit->types.empty(); /* for derived tables & PS (which can't be reset by Item_subquery) */ unit->reinit_exec_mechanism(); unit->set_thd(thd); } } /* TODO: When the new table structure is ready, then have a status bit to indicate the table is altered, and re-do the setup_* and open the tables back. */ /* NOTE: We should reset whole table list here including all tables added by prelocking algorithm (it is not a problem for substatements since they have their own table list). */ for (TABLE_LIST *tables= lex->query_tables; tables; tables= tables->next_global) { tables->reinit_before_use(thd); } /* Cleanup of the special case of DELETE t1, t2 FROM t1, t2, t3 ... (multi-delete). We do a full clean up, although at the moment all we need to clean in the tables of MULTI-DELETE list is 'table' member. */ for (TABLE_LIST *tables= (TABLE_LIST*) lex->auxiliary_table_list.first; tables; tables= tables->next_global) { tables->reinit_before_use(thd); } lex->current_select= &lex->select_lex; /* restore original list used in INSERT ... SELECT */ if (lex->leaf_tables_insert) lex->select_lex.leaf_tables= lex->leaf_tables_insert; if (lex->result) { lex->result->cleanup(); lex->result->set_thd(thd); } lex->allow_sum_func= 0; lex->in_sum_func= NULL; DBUG_VOID_RETURN; } /** Clears parameters from data left from previous execution or long data. @param stmt prepared statement for which parameters should be reset */ static void reset_stmt_params(Prepared_statement *stmt) { Item_param **item= stmt->param_array; Item_param **end= item + stmt->param_count; for (;item < end ; ++item) (**item).reset(); } /** COM_STMT_EXECUTE handler: execute a previously prepared statement. If there are any parameters, then replace parameter markers with the data supplied from the client, and then execute the statement. This function uses binary protocol to send a possible result set to the client. @param thd current thread @param packet_arg parameter types and data, if any @param packet_length packet length, including the terminator character. @return none: in case of success OK packet or a result set is sent to the client, otherwise an error message is set in THD. */ void mysql_stmt_execute(THD *thd, char *packet_arg, uint packet_length) { uchar *packet= (uchar*)packet_arg; // GCC 4.0.1 workaround ulong stmt_id= uint4korr(packet); ulong flags= (ulong) packet[4]; /* Query text for binary, general or slow log, if any of them is open */ String expanded_query; #ifndef EMBEDDED_LIBRARY uchar *packet_end= packet + packet_length; #endif Prepared_statement *stmt; bool error; DBUG_ENTER("mysql_stmt_execute"); packet+= 9; /* stmt_id + 5 bytes of flags */ /* First of all clear possible warnings from the previous command */ mysql_reset_thd_for_next_command(thd); if (!(stmt= find_prepared_statement(thd, stmt_id, "mysql_stmt_execute"))) DBUG_VOID_RETURN; DBUG_PRINT("exec_query", ("%s", stmt->query)); DBUG_PRINT("info",("stmt: 0x%lx", (long) stmt)); sp_cache_flush_obsolete(&thd->sp_proc_cache); sp_cache_flush_obsolete(&thd->sp_func_cache); #ifndef EMBEDDED_LIBRARY if (stmt->param_count) { uchar *null_array= packet; if (setup_conversion_functions(stmt, &packet, packet_end) || stmt->set_params(stmt, null_array, packet, packet_end, &expanded_query)) goto set_params_data_err; } #else /* In embedded library we re-install conversion routines each time we set params, and also we don't need to parse packet. So we do it in one function. */ if (stmt->param_count && stmt->set_params_data(stmt, &expanded_query)) goto set_params_data_err; #endif if (!(specialflag & SPECIAL_NO_PRIOR)) my_pthread_setprio(pthread_self(),QUERY_PRIOR); /* If the free_list is not empty, we'll wrongly free some externally allocated items when cleaning up after validation of the prepared statement. */ DBUG_ASSERT(thd->free_list == NULL); error= stmt->execute(&expanded_query, test(flags & (ulong) CURSOR_TYPE_READ_ONLY)); if (!(specialflag & SPECIAL_NO_PRIOR)) my_pthread_setprio(pthread_self(), WAIT_PRIOR); DBUG_VOID_RETURN; set_params_data_err: my_error(ER_WRONG_ARGUMENTS, MYF(0), "mysql_stmt_execute"); reset_stmt_params(stmt); DBUG_VOID_RETURN; } /** SQLCOM_EXECUTE implementation. Execute prepared statement using parameter values from lex->prepared_stmt_params and send result to the client using text protocol. This is called from mysql_execute_command and therefore should behave like an ordinary query (e.g. not change global THD data, such as warning count, server status, etc). This function uses text protocol to send a possible result set. @param thd thread handle @return none: in case of success, OK (or result set) packet is sent to the client, otherwise an error is set in THD */ void mysql_sql_stmt_execute(THD *thd) { LEX *lex= thd->lex; Prepared_statement *stmt; LEX_STRING *name= &lex->prepared_stmt_name; /* Query text for binary, general or slow log, if any of them is open */ String expanded_query; DBUG_ENTER("mysql_sql_stmt_execute"); DBUG_PRINT("info", ("EXECUTE: %.*s\n", (int) name->length, name->str)); if (!(stmt= (Prepared_statement*) thd->stmt_map.find_by_name(name))) { my_error(ER_UNKNOWN_STMT_HANDLER, MYF(0), name->length, name->str, "EXECUTE"); DBUG_VOID_RETURN; } if (stmt->param_count != lex->prepared_stmt_params.elements) { my_error(ER_WRONG_ARGUMENTS, MYF(0), "EXECUTE"); DBUG_VOID_RETURN; } DBUG_PRINT("info",("stmt: 0x%lx", (long) stmt)); /* If the free_list is not empty, we'll wrongly free some externally allocated items when cleaning up after validation of the prepared statement. */ DBUG_ASSERT(thd->free_list == NULL); if (stmt->set_params_from_vars(stmt, lex->prepared_stmt_params, &expanded_query)) goto set_params_data_err; (void) stmt->execute(&expanded_query, FALSE); DBUG_VOID_RETURN; set_params_data_err: my_error(ER_WRONG_ARGUMENTS, MYF(0), "EXECUTE"); reset_stmt_params(stmt); DBUG_VOID_RETURN; } /** COM_STMT_FETCH handler: fetches requested amount of rows from cursor. @param thd Thread handle @param packet Packet from client (with stmt_id & num_rows) @param packet_length Length of packet */ void mysql_stmt_fetch(THD *thd, char *packet, uint packet_length) { /* assume there is always place for 8-16 bytes */ ulong stmt_id= uint4korr(packet); ulong num_rows= uint4korr(packet+4); Prepared_statement *stmt; Statement stmt_backup; Server_side_cursor *cursor; DBUG_ENTER("mysql_stmt_fetch"); /* First of all clear possible warnings from the previous command */ mysql_reset_thd_for_next_command(thd); status_var_increment(thd->status_var.com_stmt_fetch); if (!(stmt= find_prepared_statement(thd, stmt_id, "mysql_stmt_fetch"))) DBUG_VOID_RETURN; cursor= stmt->cursor; if (!cursor) { my_error(ER_STMT_HAS_NO_OPEN_CURSOR, MYF(0), stmt_id); DBUG_VOID_RETURN; } thd->stmt_arena= stmt; thd->set_n_backup_statement(stmt, &stmt_backup); if (!(specialflag & SPECIAL_NO_PRIOR)) my_pthread_setprio(pthread_self(), QUERY_PRIOR); cursor->fetch(num_rows); if (!(specialflag & SPECIAL_NO_PRIOR)) my_pthread_setprio(pthread_self(), WAIT_PRIOR); if (!cursor->is_open()) { stmt->close_cursor(); thd->cursor= 0; reset_stmt_params(stmt); } thd->restore_backup_statement(stmt, &stmt_backup); thd->stmt_arena= thd; DBUG_VOID_RETURN; } /** Reset a prepared statement in case there was a recoverable error. This function resets statement to the state it was right after prepare. It can be used to: - clear an error happened during mysql_stmt_send_long_data - cancel long data stream for all placeholders without having to call mysql_stmt_execute. - close an open cursor Sends 'OK' packet in case of success (statement was reset) or 'ERROR' packet (unrecoverable error/statement not found/etc). @param thd Thread handle @param packet Packet with stmt id */ void mysql_stmt_reset(THD *thd, char *packet) { /* There is always space for 4 bytes in buffer */ ulong stmt_id= uint4korr(packet); Prepared_statement *stmt; DBUG_ENTER("mysql_stmt_reset"); /* First of all clear possible warnings from the previous command */ mysql_reset_thd_for_next_command(thd); status_var_increment(thd->status_var.com_stmt_reset); if (!(stmt= find_prepared_statement(thd, stmt_id, "mysql_stmt_reset"))) DBUG_VOID_RETURN; stmt->close_cursor(); /* Clear parameters from data which could be set by mysql_stmt_send_long_data() call. */ reset_stmt_params(stmt); stmt->state= Query_arena::PREPARED; send_ok(thd); DBUG_VOID_RETURN; } /** Delete a prepared statement from memory. @note we don't send any reply to this command. */ void mysql_stmt_close(THD *thd, char *packet) { /* There is always space for 4 bytes in packet buffer */ ulong stmt_id= uint4korr(packet); Prepared_statement *stmt; DBUG_ENTER("mysql_stmt_close"); if (!(stmt= find_prepared_statement(thd, stmt_id, "mysql_stmt_close"))) DBUG_VOID_RETURN; /* The only way currently a statement can be deallocated when it's in use is from within Dynamic SQL. */ DBUG_ASSERT(! (stmt->flags & (uint) Prepared_statement::IS_IN_USE)); (void) stmt->deallocate(); DBUG_VOID_RETURN; } /** SQLCOM_DEALLOCATE implementation. Close an SQL prepared statement. As this can be called from Dynamic SQL, we should be careful to not close a statement that is currently being executed. @return none: OK packet is sent in case of success, otherwise an error message is set in THD */ void mysql_sql_stmt_close(THD *thd) { Prepared_statement* stmt; LEX_STRING *name= &thd->lex->prepared_stmt_name; DBUG_PRINT("info", ("DEALLOCATE PREPARE: %.*s\n", (int) name->length, name->str)); if (! (stmt= (Prepared_statement*) thd->stmt_map.find_by_name(name))) { my_error(ER_UNKNOWN_STMT_HANDLER, MYF(0), name->length, name->str, "DEALLOCATE PREPARE"); return; } if (stmt->deallocate() == 0) send_ok(thd); } /** Handle long data in pieces from client. Get a part of a long data. To make the protocol efficient, we are not sending any return packets here. If something goes wrong, then we will send the error on 'execute' We assume that the client takes care of checking that all parts are sent to the server. (No checking that we get a 'end of column' in the server is performed). @param thd Thread handle @param packet String to append @param packet_length Length of string (including end \\0) */ void mysql_stmt_get_longdata(THD *thd, char *packet, ulong packet_length) { ulong stmt_id; uint param_number; Prepared_statement *stmt; Item_param *param; #ifndef EMBEDDED_LIBRARY char *packet_end= packet + packet_length; #endif DBUG_ENTER("mysql_stmt_get_longdata"); status_var_increment(thd->status_var.com_stmt_send_long_data); #ifndef EMBEDDED_LIBRARY /* Minimal size of long data packet is 6 bytes */ if (packet_length < MYSQL_LONG_DATA_HEADER) { my_error(ER_WRONG_ARGUMENTS, MYF(0), "mysql_stmt_send_long_data"); DBUG_VOID_RETURN; } #endif stmt_id= uint4korr(packet); packet+= 4; if (!(stmt=find_prepared_statement(thd, stmt_id, "mysql_stmt_send_long_data"))) DBUG_VOID_RETURN; param_number= uint2korr(packet); packet+= 2; #ifndef EMBEDDED_LIBRARY if (param_number >= stmt->param_count) { /* Error will be sent in execute call */ stmt->state= Query_arena::ERROR; stmt->last_errno= ER_WRONG_ARGUMENTS; sprintf(stmt->last_error, ER(ER_WRONG_ARGUMENTS), "mysql_stmt_send_long_data"); DBUG_VOID_RETURN; } #endif param= stmt->param_array[param_number]; #ifndef EMBEDDED_LIBRARY if (param->set_longdata(packet, (ulong) (packet_end - packet))) #else if (param->set_longdata(thd->extra_data, thd->extra_length)) #endif { stmt->state= Query_arena::ERROR; stmt->last_errno= ER_OUTOFMEMORY; sprintf(stmt->last_error, ER(ER_OUTOFMEMORY), 0); } DBUG_VOID_RETURN; } /*************************************************************************** Select_fetch_protocol_binary ****************************************************************************/ Select_fetch_protocol_binary::Select_fetch_protocol_binary(THD *thd_arg) :protocol(thd_arg) {} bool Select_fetch_protocol_binary::send_fields(List<Item> &list, uint flags) { bool rc; Protocol *save_protocol= thd->protocol; /* Protocol::send_fields caches the information about column types: this information is later used to send data. Therefore, the same dedicated Protocol object must be used for all operations with a cursor. */ thd->protocol= &protocol; rc= select_send::send_fields(list, flags); thd->protocol= save_protocol; return rc; } bool Select_fetch_protocol_binary::send_eof() { Protocol *save_protocol= thd->protocol; thd->protocol= &protocol; ::send_eof(thd); thd->protocol= save_protocol; return FALSE; } bool Select_fetch_protocol_binary::send_data(List<Item> &fields) { Protocol *save_protocol= thd->protocol; bool rc; thd->protocol= &protocol; rc= select_send::send_data(fields); thd->protocol= save_protocol; return rc; } /*************************************************************************** Prepared_statement ****************************************************************************/ Prepared_statement::Prepared_statement(THD *thd_arg, Protocol *protocol_arg) :Statement(&main_lex, &main_mem_root, INITIALIZED, ++thd_arg->statement_id_counter), thd(thd_arg), result(thd_arg), protocol(protocol_arg), param_array(0), param_count(0), last_errno(0), flags((uint) IS_IN_USE) { init_sql_alloc(&main_mem_root, thd_arg->variables.query_alloc_block_size, thd_arg->variables.query_prealloc_size); *last_error= '\0'; } void Prepared_statement::setup_set_params() { /* Note: BUG#25843 applies here too (query cache lookup uses thd->db, not db from "prepare" time). */ if (query_cache_maybe_disabled(thd)) // we won't expand the query lex->safe_to_cache_query= FALSE; // so don't cache it at Execution /* Decide if we have to expand the query (because we must write it to logs or because we want to look it up in the query cache) or not. */ if (mysql_bin_log.is_open() && is_update_query(lex->sql_command) || opt_log || opt_slow_log || query_cache_is_cacheable_query(lex)) { set_params_from_vars= insert_params_from_vars_with_log; #ifndef EMBEDDED_LIBRARY set_params= insert_params_with_log; #else set_params_data= emb_insert_params_with_log; #endif } else { set_params_from_vars= insert_params_from_vars; #ifndef EMBEDDED_LIBRARY set_params= insert_params; #else set_params_data= emb_insert_params; #endif } } /** Destroy this prepared statement, cleaning up all used memory and resources. This is called from ::deallocate() to handle COM_STMT_CLOSE and DEALLOCATE PREPARE or when THD ends and all prepared statements are freed. */ Prepared_statement::~Prepared_statement() { DBUG_ENTER("Prepared_statement::~Prepared_statement"); DBUG_PRINT("enter",("stmt: 0x%lx cursor: 0x%lx", (long) this, (long) cursor)); delete cursor; /* We have to call free on the items even if cleanup is called as some items, like Item_param, don't free everything until free_items() */ free_items(); delete lex->result; free_root(&main_mem_root, MYF(0)); DBUG_VOID_RETURN; } Query_arena::Type Prepared_statement::type() const { return PREPARED_STATEMENT; } void Prepared_statement::cleanup_stmt() { DBUG_ENTER("Prepared_statement::cleanup_stmt"); DBUG_PRINT("enter",("stmt: 0x%lx", (long) this)); DBUG_ASSERT(lex->sphead == 0); /* The order is important */ lex->unit.cleanup(); cleanup_items(free_list); thd->cleanup_after_query(); close_thread_tables(thd); thd->rollback_item_tree_changes(); DBUG_VOID_RETURN; } bool Prepared_statement::set_name(LEX_STRING *name_arg) { name.length= name_arg->length; name.str= (char*) memdup_root(mem_root, name_arg->str, name_arg->length); return name.str == 0; } /************************************************************************** Common parts of mysql_[sql]_stmt_prepare, mysql_[sql]_stmt_execute. Essentially, these functions do all the magic of preparing/executing a statement, leaving network communication, input data handling and global THD state management to the caller. ***************************************************************************/ /** Parse statement text, validate the statement, and prepare it for execution. You should not change global THD state in this function, if at all possible: it may be called from any context, e.g. when executing a COM_* command, and SQLCOM_* command, or a stored procedure. @param packet statement text @param packet_len @note Precondition: The caller must ensure that thd->change_list and thd->free_list is empty: this function will not back them up but will free in the end of its execution. @note Postcondition: thd->mem_root contains unused memory allocated during validation. */ bool Prepared_statement::prepare(const char *packet, uint packet_len) { bool error; Statement stmt_backup; Query_arena *old_stmt_arena; DBUG_ENTER("Prepared_statement::prepare"); /* If this is an SQLCOM_PREPARE, we also increase Com_prepare_sql. However, it seems handy if com_stmt_prepare is increased always, no matter what kind of prepare is processed. */ status_var_increment(thd->status_var.com_stmt_prepare); /* alloc_query() uses thd->memroot && thd->query, so we should call both of backup_statement() and backup_query_arena() here. */ thd->set_n_backup_statement(this, &stmt_backup); thd->set_n_backup_active_arena(this, &stmt_backup); if (alloc_query(thd, packet, packet_len)) { thd->restore_backup_statement(this, &stmt_backup); thd->restore_active_arena(this, &stmt_backup); DBUG_RETURN(TRUE); } old_stmt_arena= thd->stmt_arena; thd->stmt_arena= this; Lex_input_stream lip(thd, thd->query, thd->query_length); lip.stmt_prepare_mode= TRUE; lex_start(thd); error= parse_sql(thd, &lip, NULL) || thd->is_error() || init_param_array(this); lex->set_trg_event_type_for_tables(); /* Remember the current database. */ if (thd->db && thd->db_length) { db= this->strmake(thd->db, thd->db_length); db_length= thd->db_length; } else { db= NULL; db_length= 0; } /* While doing context analysis of the query (in check_prepared_statement) we allocate a lot of additional memory: for open tables, JOINs, derived tables, etc. Let's save a snapshot of current parse tree to the statement and restore original THD. In cases when some tree transformation can be reused on execute, we set again thd->mem_root from stmt->mem_root (see setup_wild for one place where we do that). */ thd->restore_active_arena(this, &stmt_backup); /* If called from a stored procedure, ensure that we won't rollback external changes when cleaning up after validation. */ DBUG_ASSERT(thd->change_list.is_empty()); /* The only case where we should have items in the thd->free_list is after stmt->set_params_from_vars(), which may in some cases create Item_null objects. */ if (error == 0) error= check_prepared_statement(this, name.str != 0); /* Currently CREATE PROCEDURE/TRIGGER/EVENT are prohibited in prepared statements: ensure we have no memory leak here if by someone tries to PREPARE stmt FROM "CREATE PROCEDURE ..." */ DBUG_ASSERT(lex->sphead == NULL || error != 0); if (lex->sphead) { delete lex->sphead; lex->sphead= NULL; } lex_end(lex); cleanup_stmt(); thd->restore_backup_statement(this, &stmt_backup); thd->stmt_arena= old_stmt_arena; if (error == 0) { setup_set_params(); init_stmt_after_parse(lex); state= Query_arena::PREPARED; flags&= ~ (uint) IS_IN_USE; /* Log COM_EXECUTE to the general log. Note, that in case of SQL prepared statements this causes two records to be output: Query PREPARE stmt from @user_variable Prepare <statement SQL text> This is considered user-friendly, since in the second log entry we output the actual statement text. Do not print anything if this is an SQL prepared statement and we're inside a stored procedure (also called Dynamic SQL) -- sub-statements inside stored procedures are not logged into the general log. */ if (thd->spcont == NULL) general_log_write(thd, COM_STMT_PREPARE, query, query_length); } DBUG_RETURN(error); } /** Execute a prepared statement. You should not change global THD state in this function, if at all possible: it may be called from any context, e.g. when executing a COM_* command, and SQLCOM_* command, or a stored procedure. @param expanded_query A query for binlogging which has all parameter markers ('?') replaced with their actual values. @param open_cursor True if an attempt to open a cursor should be made. Currenlty used only in the binary protocol. @note Preconditions, postconditions. - See the comment for Prepared_statement::prepare(). @retval FALSE ok @retval TRUE Error */ bool Prepared_statement::execute(String *expanded_query, bool open_cursor) { Statement stmt_backup; Query_arena *old_stmt_arena; bool error= TRUE; char saved_cur_db_name_buf[NAME_LEN+1]; LEX_STRING saved_cur_db_name= { saved_cur_db_name_buf, sizeof(saved_cur_db_name_buf) }; bool cur_db_changed; LEX_STRING stmt_db_name= { db, db_length }; status_var_increment(thd->status_var.com_stmt_execute); /* Check if we got an error when sending long data */ if (state == Query_arena::ERROR) { my_message(last_errno, last_error, MYF(0)); return TRUE; } if (flags & (uint) IS_IN_USE) { my_error(ER_PS_NO_RECURSION, MYF(0)); return TRUE; } /* For SHOW VARIABLES lex->result is NULL, as it's a non-SELECT command. For such queries we don't return an error and don't open a cursor -- the client library will recognize this case and materialize the result set. For SELECT statements lex->result is created in check_prepared_statement. lex->result->simple_select() is FALSE in INSERT ... SELECT and similar commands. */ if (open_cursor && lex->result && lex->result->check_simple_select()) { DBUG_PRINT("info",("Cursor asked for not SELECT stmt")); return TRUE; } /* In case the command has a call to SP which re-uses this statement name */ flags|= IS_IN_USE; close_cursor(); /* If the free_list is not empty, we'll wrongly free some externally allocated items when cleaning up after execution of this statement. */ DBUG_ASSERT(thd->change_list.is_empty()); /* The only case where we should have items in the thd->free_list is after stmt->set_params_from_vars(), which may in some cases create Item_null objects. */ thd->set_n_backup_statement(this, &stmt_backup); /* Change the current database (if needed). Force switching, because the database of the prepared statement may be NULL (prepared statements can be created while no current database selected). */ if (mysql_opt_change_db(thd, &stmt_db_name, &saved_cur_db_name, TRUE, &cur_db_changed)) goto error; /* Allocate query. */ if (expanded_query->length() && alloc_query(thd, (char*) expanded_query->ptr(), expanded_query->length())) { my_error(ER_OUTOFMEMORY, 0, expanded_query->length()); goto error; } /* Expanded query is needed for slow logging, so we want thd->query to point at it even after we restore from backup. This is ok, as expanded query was allocated in thd->mem_root. */ stmt_backup.query= thd->query; stmt_backup.query_length= thd->query_length; /* At first execution of prepared statement we may perform logical transformations of the query tree. Such changes should be performed on the parse tree of current prepared statement and new items should be allocated in its memory root. Set the appropriate pointer in THD to the arena of the statement. */ old_stmt_arena= thd->stmt_arena; thd->stmt_arena= this; reinit_stmt_before_use(thd, lex); thd->protocol= protocol; /* activate stmt protocol */ /* Go! */ if (open_cursor) error= mysql_open_cursor(thd, (uint) ALWAYS_MATERIALIZED_CURSOR, &result, &cursor); else { /* Try to find it in the query cache, if not, execute it. Note that multi-statements cannot exist here (they are not supported in prepared statements). */ if (query_cache_send_result_to_client(thd, thd->query, thd->query_length) <= 0) { error= mysql_execute_command(thd); query_cache_end_of_result(thd); } } /* Restore the current database (if changed). Force switching back to the saved current database (if changed), because it may be NULL. In this case, mysql_change_db() would generate an error. */ if (cur_db_changed) mysql_change_db(thd, &saved_cur_db_name, TRUE); thd->protocol= &thd->protocol_text; /* use normal protocol */ /* Assert that if an error, no cursor is open */ DBUG_ASSERT(! (error && cursor)); if (! cursor) { cleanup_stmt(); reset_stmt_params(this); } thd->set_statement(&stmt_backup); thd->stmt_arena= old_stmt_arena; if (state == Query_arena::PREPARED) state= Query_arena::EXECUTED; /* Log COM_EXECUTE to the general log. Note, that in case of SQL prepared statements this causes two records to be output: Query EXECUTE <statement name> Execute <statement SQL text> This is considered user-friendly, since in the second log entry we output values of parameter markers. Do not print anything if this is an SQL prepared statement and we're inside a stored procedure (also called Dynamic SQL) -- sub-statements inside stored procedures are not logged into the general log. */ if (error == 0 && thd->spcont == NULL) general_log_write(thd, COM_STMT_EXECUTE, thd->query, thd->query_length); error: flags&= ~ (uint) IS_IN_USE; return error; } /** Common part of DEALLOCATE PREPARE and mysql_stmt_close. */ bool Prepared_statement::deallocate() { /* We account deallocate in the same manner as mysql_stmt_close */ status_var_increment(thd->status_var.com_stmt_close); if (flags & (uint) IS_IN_USE) { my_error(ER_PS_NO_RECURSION, MYF(0)); return TRUE; } /* Statement map calls delete stmt on erase */ thd->stmt_map.erase(this); return FALSE; }