SQL: VTMD for SHOW CREATE fixes [related to #125]

mysql-test/suite/versioning/r/vtmd_show.result

@@ -51,7 +51,7 @@ drop table tt_vtmd;
 end~~
 create table t (a int) with system versioning;
 show create table t for system_time as of now;
-ERROR 42S02: Table 'test.t_vtmd' doesn't exist
+ERROR HY000: VTMD error: Table 'test.t_vtmd' doesn't exist
 set versioning_alter_history=survive;
 create or replace table t (a int) with system versioning;
 show create table t for system_time between timestamp @tm1 and timestamp @tm1;
@@ -59,9 +59,9 @@ ERROR HY000: SYSTEM_TIME range selector is prohibited
 show create table t for system_time from timestamp @tm1 to timestamp @tm1;
 ERROR HY000: SYSTEM_TIME range selector is prohibited
 show create table t for system_time as of timestamp '01-01-1990';
-ERROR HY000: VTMD error: failed to query VTMD table
+ERROR HY000: VTMD error: Table 'test.t' doesn't exist
 show create table t for system_time as of timestamp '01-01-2020';
-ERROR HY000: VTMD error: failed to query VTMD table
+ERROR HY000: VTMD error: Table 'test.t' doesn't exist
 drop table t;
 call drop_archives('t_vtmd');
 drop table t_vtmd;

mysql-test/suite/versioning/t/vtmd_show.test

@@ -65,7 +65,7 @@ end~~
 delimiter ;~~
 
 create table t (a int) with system versioning;
---error ER_NO_SUCH_TABLE
+--error ER_VERS_VTMD_ERROR
 show create table t for system_time as of now;
 
 set versioning_alter_history=survive;

sql/sql_show.cc

@@ -1270,23 +1270,22 @@ mysqld_show_create(THD *thd, TABLE_LIST *table_list)
   */
   MDL_savepoint mdl_savepoint= thd->mdl_context.mdl_savepoint();
 
-  TABLE_LIST tl;
-  bool versioned_query=
-      table_list->vers_conditions.type != FOR_SYSTEM_TIME_UNSPECIFIED;
-  String archive_name;
-  if (versioned_query)
+  TABLE_LIST archive;
+  bool versioned= table_list->vers_conditions;
+  if (versioned)
   {
-    DBUG_ASSERT(table_list->vers_conditions.type == FOR_SYSTEM_TIME_AS_OF);
+    String archive_name;
+    DBUG_ASSERT(table_list->vers_conditions == FOR_SYSTEM_TIME_AS_OF);
     VTMD_table vtmd(*table_list);
     if (vtmd.find_archive_name(thd, archive_name))
       goto exit;
 
-    tl.init_one_table(table_list->db, table_list->db_length, archive_name.ptr(),
+    archive.init_one_table(table_list->db, table_list->db_length, archive_name.ptr(),
                       archive_name.length(), archive_name.ptr(), TL_READ);
 
-    tl.alias= table_list->table_name;
-    tl.vers_force_alias= true;
-    table_list= &tl;
+    archive.alias= table_list->table_name;
+    archive.vers_force_alias= true;
+    table_list= &archive;
   }
 
   if (mysqld_show_create_get_fields(thd, table_list, &field_list, &buffer))
@@ -1302,9 +1301,7 @@ mysqld_show_create(THD *thd, TABLE_LIST *table_list)
     protocol->store(table_list->view_name.str, system_charset_info);
   else
   {
-    if (versioned_query)
-      protocol->store(tl.alias, system_charset_info);
-    else if (table_list->schema_table)
+    if (table_list->schema_table)
       protocol->store(table_list->schema_table->table_name,
                       system_charset_info);
     else
@@ -1332,7 +1329,7 @@ mysqld_show_create(THD *thd, TABLE_LIST *table_list)
   my_eof(thd);
 
 exit:
-  if (versioned_query)
+  if (versioned)
   {
     /* If commit fails, we should be able to reset the OK status. */
     thd->get_stmt_da()->set_overwrite_status(true);

sql/vtmd.h

@@ -48,8 +48,10 @@ class THD;
 
 class VTMD_table
 {
+  Open_tables_backup open_tables_backup;
+
 protected:
-  TABLE *vtmd;
+  TABLE_LIST vtmd;
   const TABLE_LIST &about;
   SString_t vtmd_name;
 
@@ -72,13 +74,16 @@ class VTMD_table
   };
 
   VTMD_table(TABLE_LIST &_about) :
-    vtmd(NULL),
     about(_about)
-  {}
+  {
+    vtmd.table= NULL;
+  }
 
   bool create(THD *thd);
   bool find_record(ulonglong sys_trx_end, bool &found);
+  bool open(THD *thd, Local_da &local_da, bool *created= NULL);
   bool update(THD *thd, const char* archive_name= NULL);
+  bool setup_select(THD *thd);
 
   static void archive_name(THD *thd, const char *table_name, char *new_name, size_t new_name_size);
   void archive_name(THD *thd, char *new_name, size_t new_name_size)