Fix bug #3443, better foreign key error messsages.

innobase/dict/dict0dict.c

@@ -2189,7 +2189,7 @@ dict_foreign_error_report(
 	dict_foreign_error_report_low(file, fk->foreign_table_name);
 	fputs(msg, file);
 	fputs(" Constraint:\n", file);
-	dict_print_info_on_foreign_key_in_create_format(file, NULL, fk);
+	dict_print_info_on_foreign_key_in_create_format(file, NULL, fk, TRUE);
 	if (fk->foreign_index) {
 		fputs("\nThe index in the foreign key in table is ", file);
 		ut_print_name(file, NULL, fk->foreign_index->name);
@@ -4332,7 +4332,8 @@ dict_print_info_on_foreign_key_in_create_format(
 /*============================================*/
 	FILE*		file,		/* in: file where to print */
 	trx_t*		trx,		/* in: transaction */
-	dict_foreign_t*	foreign)/* in: foreign key constraint */
+	dict_foreign_t*	foreign,	/* in: foreign key constraint */
+	ibool		add_newline)	/* in: whether to add a newline */
 {
 	const char*	stripped_id;
 	ulint	i;
@@ -4345,7 +4346,16 @@ dict_print_info_on_foreign_key_in_create_format(
 		stripped_id = foreign->id;
 	}
 
-	fputs(",\n  CONSTRAINT ", file);
+	putc(',', file);
+	
+	if (add_newline) {
+		/* SHOW CREATE TABLE wants constraints each printed nicely
+		on its own line, while error messages want no newlines
+		inserted. */
+		fputs("\n ", file);
+	}
+	
+	fputs(" CONSTRAINT ", file);
 	ut_print_name(file, trx, stripped_id);
 	fputs(" FOREIGN KEY (", file);
 
@@ -4447,7 +4457,7 @@ dict_print_info_on_foreign_keys(
 	while (foreign != NULL) {
 		if (create_table_format) {
 			dict_print_info_on_foreign_key_in_create_format(
-						file, trx, foreign);
+						file, trx, foreign, TRUE);
 		} else {
 			ulint	i;
 			fputs("; (", file);

innobase/include/dict0dict.h

@@ -377,7 +377,8 @@ dict_print_info_on_foreign_key_in_create_format(
 /*============================================*/
 	FILE*		file,		/* in: file where to print */
 	trx_t*		trx,		/* in: transaction */
-	dict_foreign_t*	foreign);/* in: foreign key constraint */
+	dict_foreign_t*	foreign,	/* in: foreign key constraint */
+	ibool		add_newline);	/* in: whether to add a newline */
 /************************************************************************
 Displays the names of the index and the table. */
 void

innobase/include/os0file.h

@@ -432,6 +432,17 @@ os_file_read(
 				offset */
 	ulint		n);	/* in: number of bytes to read */	
 /***********************************************************************
+Rewind file to its start, read at most size - 1 bytes from it to str, and
+NUL-terminate str. All errors are silently ignored. This function is
+mostly meant to be used with temporary files. */
+
+void
+os_file_read_string(
+/*================*/
+	FILE*	file,	/* in: file to read from */
+	char*	str,	/* in: buffer where to read */
+	ulint	size);	/* in: size of buffer */
+/***********************************************************************
 Requests a synchronous positioned read operation. This function does not do
 any error handling. In case of error it returns FALSE. */
 

innobase/include/trx0trx.h

@@ -56,6 +56,22 @@ void
 trx_search_latch_release_if_reserved(
 /*=================================*/
         trx_t*     trx); /* in: transaction */
+/**********************************************************************
+Set detailed error message for the transaction. */
+void
+trx_set_detailed_error(
+/*===================*/
+	trx_t*	trx,	/* in: transaction struct */
+	char*	msg);	/* in: detailed error message */
+/*****************************************************************
+Set detailed error message for the transaction from a file. Note that the
+file is rewinded before reading from it. */
+
+void
+trx_set_detailed_error_from_file(
+/*=============================*/
+	trx_t*	trx,	/* in: transaction struct */
+	FILE*	file);	/* in: file to read message from */
 /********************************************************************
 Retrieves the error_info field from a trx. */
 
@@ -649,6 +665,9 @@ struct trx_struct{
 	trx_undo_arr_t*	undo_no_arr;	/* array of undo numbers of undo log
 					records which are currently processed
 					by a rollback operation */
+	/*------------------------------*/
+	char detailed_error[256];	/* detailed error message for last
+					error, or empty. */
 };
 
 #define TRX_MAX_N_THREADS	32	/* maximum number of concurrent

innobase/include/ut0mem.h

@@ -118,6 +118,18 @@ UNIV_INLINE
 int
 ut_strcmp(const void* str1, const void* str2);
 
+/**************************************************************************
+Copies up to size - 1 characters from the NUL-terminated string src to
+dst, NUL-terminating the result. Returns strlen(src), so truncation
+occurred if the return value >= size. */
+ulint
+ut_strlcpy(
+/*=======*/
+				/* out: strlen(src) */
+	char*		dst,	/* in: destination buffer */
+	const char*	src,	/* in: source buffer */
+	ulint		size);	/* in: size of destination buffer */
+
 /**************************************************************************
 Compute strlen(ut_strcpyq(str, q)). */
 UNIV_INLINE

innobase/os/os0file.c

@@ -2248,6 +2248,29 @@ os_file_read_no_error_handling(
 	return(FALSE);
 }
 
+/***********************************************************************
+Rewind file to its start, read at most size - 1 bytes from it to str, and
+NUL-terminate str. All errors are silently ignored. This function is
+mostly meant to be used with temporary files. */
+
+void
+os_file_read_string(
+/*================*/
+	FILE*	file,	/* in: file to read from */
+	char*	str,	/* in: buffer where to read */
+	ulint	size)	/* in: size of buffer */
+{
+	size_t	flen;
+
+	if (size == 0) {
+		return;
+	}
+	
+	rewind(file);
+	flen = fread(str, 1, size - 1, file);
+	str[flen] = '\0';
+}
+
 /***********************************************************************
 Requests a synchronous write operation. */
 

innobase/row/row0ins.c

@@ -578,6 +578,30 @@ row_ins_cascade_calc_update_vec(
 	return(n_fields_updated);
 }
 
+/*************************************************************************
+Set detailed error message associated with foreign key errors for
+the given transaction. */
+static
+void
+row_ins_set_detailed(
+/*=================*/
+	trx_t*		trx,		/* in: transaction */
+	dict_foreign_t*	foreign)	/* in: foreign key constraint */
+{
+		
+	FILE*	tf = os_file_create_tmpfile();
+
+	ut_a(tf);
+		
+	ut_print_name(tf, trx, foreign->foreign_table_name);
+	dict_print_info_on_foreign_key_in_create_format(tf, trx,
+		foreign, FALSE);
+
+	trx_set_detailed_error_from_file(trx, tf);
+
+	fclose(tf);
+}
+
 /*************************************************************************
 Reports a foreign key error associated with an update or a delete of a
 parent table index entry. */
@@ -598,6 +622,8 @@ row_ins_foreign_report_err(
 	FILE*	ef	= dict_foreign_err_file;
 	trx_t*	trx	= thr_get_trx(thr);
 
+	row_ins_set_detailed(trx, foreign);
+
 	mutex_enter(&dict_foreign_err_mutex);
 	rewind(ef);
 	ut_print_timestamp(ef);
@@ -607,7 +633,8 @@ row_ins_foreign_report_err(
 	fputs("Foreign key constraint fails for table ", ef);
 	ut_print_name(ef, trx, foreign->foreign_table_name);
 	fputs(":\n", ef);
-	dict_print_info_on_foreign_key_in_create_format(ef, trx, foreign);
+	dict_print_info_on_foreign_key_in_create_format(ef, trx, foreign,
+		TRUE);
 	putc('\n', ef);
 	fputs(errstr, ef);
 	fputs(" in parent table, in index ", ef);
@@ -649,6 +676,8 @@ row_ins_foreign_report_add_err(
 {
 	FILE*	ef	= dict_foreign_err_file;
 	
+	row_ins_set_detailed(trx, foreign);
+	
 	mutex_enter(&dict_foreign_err_mutex);
 	rewind(ef);
 	ut_print_timestamp(ef);
@@ -657,7 +686,8 @@ row_ins_foreign_report_add_err(
 	fputs("Foreign key constraint fails for table ", ef);
 	ut_print_name(ef, trx, foreign->foreign_table_name);
 	fputs(":\n", ef);
-	dict_print_info_on_foreign_key_in_create_format(ef, trx, foreign);
+	dict_print_info_on_foreign_key_in_create_format(ef, trx, foreign,
+		TRUE);
 	fputs("\nTrying to add in child table, in index ", ef);
 	ut_print_name(ef, trx, foreign->foreign_index->name);
 	if (entry) {
@@ -1223,6 +1253,8 @@ row_ins_check_foreign_constraint(
 
 	if (check_table == NULL || check_table->ibd_file_missing) {
 		if (check_ref) {
+			row_ins_set_detailed(trx, foreign);
+			
 			FILE*	ef = dict_foreign_err_file;
 			mutex_enter(&dict_foreign_err_mutex);
 			rewind(ef);
@@ -1233,7 +1265,7 @@ row_ins_check_foreign_constraint(
 			ut_print_name(ef, trx, foreign->foreign_table_name);
 			fputs(":\n", ef);
 			dict_print_info_on_foreign_key_in_create_format(ef,
-					trx, foreign);
+					trx, foreign, TRUE);
 			fputs("\nTrying to add to index ", ef);
 			ut_print_name(ef, trx, foreign->foreign_index->name);
 			fputs(" tuple:\n", ef);

innobase/trx/trx0trx.c

@@ -52,6 +52,32 @@ trx_start_if_not_started_noninline(
         trx_start_if_not_started(trx);
 }
 
+/*****************************************************************
+Set detailed error message for the transaction. */
+
+void
+trx_set_detailed_error(
+/*===================*/
+	trx_t*	trx,	/* in: transaction struct */
+	char*	msg)	/* in: detailed error message */
+{
+	ut_strlcpy(trx->detailed_error, msg, sizeof(trx->detailed_error));
+}
+
+/*****************************************************************
+Set detailed error message for the transaction from a file. Note that the
+file is rewinded before reading from it. */
+
+void
+trx_set_detailed_error_from_file(
+/*=============================*/
+	trx_t*	trx,	/* in: transaction struct */
+	FILE*	file)	/* in: file to read message from */
+{
+	os_file_read_string(file, trx->detailed_error,
+		sizeof(trx->detailed_error));
+}
+
 /********************************************************************
 Retrieves the error_info field from a trx. */
 
@@ -130,6 +156,7 @@ trx_create(
 	trx->undo_no_arr = NULL;
 	
 	trx->error_state = DB_SUCCESS;
+	trx->detailed_error[0] = '\0';
 
 	trx->sess = sess;
 	trx->que_state = TRX_QUE_RUNNING;

innobase/ut/ut0mem.c

@@ -342,6 +342,31 @@ ut_free_all_mem(void)
 	}
 }
 
+/**************************************************************************
+Copies up to size - 1 characters from the NUL-terminated string src to
+dst, NUL-terminating the result. Returns strlen(src), so truncation
+occurred if the return value >= size. */
+
+ulint
+ut_strlcpy(
+/*=======*/
+				/* out: strlen(src) */
+	char*		dst,	/* in: destination buffer */
+	const char*	src,	/* in: source buffer */
+	ulint		size)	/* in: size of destination buffer */
+{
+	ulint	src_size = strlen(src);
+
+	if (size != 0) {
+		ulint	n = ut_min(src_size, size - 1);
+		
+		memcpy(dst, src, n);
+		dst[n] = '\0';
+	}
+
+	return src_size;
+}
+
 /**************************************************************************
 Make a quoted copy of a NUL-terminated string.  Leading and trailing
 quotes will not be included; only embedded quotes will be escaped.

mysql-test/r/innodb.result

@@ -1378,9 +1378,9 @@ insert into `t2`values ( 1 ) ;
 create table `t3` (`id` int( 11 ) not null default '0',key `id` ( `id` ) ,constraint `t2_id_fk` foreign key ( `id` ) references `t2` (`id` )) engine = innodb;
 insert into `t3`values ( 1 ) ;
 delete t3,t2,t1 from t1,t2,t3 where t1.id =1 and t2.id = t1.id and t3.id = t2.id;
-ERROR 23000: Cannot delete or update a parent row: a foreign key constraint fails
+ERROR 23000: Cannot delete or update a parent row: a foreign key constraint fails (`test/t2`, CONSTRAINT `t1_id_fk` FOREIGN KEY (`id`) REFERENCES `t1` (`id`))
 update t1,t2,t3 set t3.id=5, t2.id=6, t1.id=7  where t1.id =1 and t2.id = t1.id and t3.id = t2.id;
-ERROR 23000: Cannot delete or update a parent row: a foreign key constraint fails
+ERROR 23000: Cannot delete or update a parent row: a foreign key constraint fails (`test/t2`, CONSTRAINT `t1_id_fk` FOREIGN KEY (`id`) REFERENCES `t1` (`id`))
 update t3 set  t3.id=7  where t1.id =1 and t2.id = t1.id and t3.id = t2.id;
 ERROR 42S22: Unknown column 't1.id' in 'where clause'
 drop table t3,t2,t1;
@@ -1392,7 +1392,7 @@ foreign key(pid) references t1(id) on delete cascade) engine=innodb;
 insert into t1 values(0,0),(1,0),(2,1),(3,2),(4,3),(5,4),(6,5),(7,6),
 (8,7),(9,8),(10,9),(11,10),(12,11),(13,12),(14,13),(15,14);
 delete from t1 where id=0;
-ERROR 23000: Cannot delete or update a parent row: a foreign key constraint fails
+ERROR 23000: Cannot delete or update a parent row: a foreign key constraint fails (`test/t1`, CONSTRAINT `t1_ibfk_1` FOREIGN KEY (`pid`) REFERENCES `t1` (`id`) ON DELETE CASCADE)
 delete from t1 where id=15;
 delete from t1 where id=0;
 drop table t1;
@@ -2559,3 +2559,26 @@ FOREIGN KEY (b) REFERENCES test.t1(id)
 ) ENGINE=InnoDB;
 Got one of the listed errors
 DROP TABLE t1;
+CREATE TABLE t1
+(
+id INT PRIMARY KEY
+) ENGINE=InnoDB;
+CREATE TABLE t2
+(
+v INT,
+CONSTRAINT c1 FOREIGN KEY (v) REFERENCES t1(id)
+) ENGINE=InnoDB;
+INSERT INTO t2 VALUES(2);
+ERROR 23000: Cannot add or update a child row: a foreign key constraint fails (`test/t2`, CONSTRAINT `c1` FOREIGN KEY (`v`) REFERENCES `t1` (`id`))
+INSERT INTO t1 VALUES(1);
+INSERT INTO t2 VALUES(1);
+DELETE FROM t1 WHERE id = 1;
+ERROR 23000: Cannot delete or update a parent row: a foreign key constraint fails (`test/t2`, CONSTRAINT `c1` FOREIGN KEY (`v`) REFERENCES `t1` (`id`))
+DROP TABLE t1;
+ERROR 23000: Cannot delete or update a parent row: a foreign key constraint fails
+SET FOREIGN_KEY_CHECKS=0;
+DROP TABLE t1;
+SET FOREIGN_KEY_CHECKS=1;
+INSERT INTO t2 VALUES(3);
+ERROR 23000: Cannot add or update a child row: a foreign key constraint fails (`test/t2`, CONSTRAINT `c1` FOREIGN KEY (`v`) REFERENCES `t1` (`id`))
+DROP TABLE t2;

mysql-test/t/innodb.test

@@ -978,9 +978,9 @@ create table `t2` (`id` int( 11 ) not null default '0',unique key `id` ( `id` )
 insert into `t2`values ( 1 ) ;
 create table `t3` (`id` int( 11 ) not null default '0',key `id` ( `id` ) ,constraint `t2_id_fk` foreign key ( `id` ) references `t2` (`id` )) engine = innodb;
 insert into `t3`values ( 1 ) ;
---error 1217
+--error 1451
 delete t3,t2,t1 from t1,t2,t3 where t1.id =1 and t2.id = t1.id and t3.id = t2.id;
---error 1217
+--error 1451
 update t1,t2,t3 set t3.id=5, t2.id=6, t1.id=7  where t1.id =1 and t2.id = t1.id and t3.id = t2.id;
 --error 1054
 update t3 set  t3.id=7  where t1.id =1 and t2.id = t1.id and t3.id = t2.id;
@@ -996,7 +996,7 @@ create table t1(
 	foreign key(pid) references t1(id) on delete cascade) engine=innodb;
 insert into t1 values(0,0),(1,0),(2,1),(3,2),(4,3),(5,4),(6,5),(7,6),
 	(8,7),(9,8),(10,9),(11,10),(12,11),(13,12),(14,13),(15,14);
--- error 1217
+-- error 1451
 delete from t1 where id=0;
 delete from t1 where id=15;
 delete from t1 where id=0;
@@ -1482,3 +1482,39 @@ CREATE TEMPORARY TABLE t2
  FOREIGN KEY (b) REFERENCES test.t1(id)
 ) ENGINE=InnoDB;
 DROP TABLE t1;
+
+#
+# Test improved foreign key error messages (bug #3443)
+#
+
+CREATE TABLE t1
+(
+ id INT PRIMARY KEY
+) ENGINE=InnoDB;
+
+CREATE TABLE t2
+(
+ v INT,
+ CONSTRAINT c1 FOREIGN KEY (v) REFERENCES t1(id)
+) ENGINE=InnoDB;
+
+--error 1452
+INSERT INTO t2 VALUES(2);
+
+INSERT INTO t1 VALUES(1);
+INSERT INTO t2 VALUES(1);
+
+--error 1451
+DELETE FROM t1 WHERE id = 1;
+
+--error 1217
+DROP TABLE t1;
+
+SET FOREIGN_KEY_CHECKS=0;
+DROP TABLE t1;
+SET FOREIGN_KEY_CHECKS=1;
+
+--error 1452
+INSERT INTO t2 VALUES(3);
+
+DROP TABLE t2;

sql/ha_innodb.cc

@@ -6065,6 +6065,8 @@ ha_innobase::start_stmt(
 		}
 	}
 
+	trx->detailed_error[0] = '\0';
+
 	/* Set the MySQL flag to mark that there is an active transaction */
         if (trx->active_trans == 0) {
 
@@ -6138,6 +6140,8 @@ ha_innobase::external_lock(
 	if (lock_type != F_UNLCK) {
 		/* MySQL is setting a new table lock */
 
+		trx->detailed_error[0] = '\0';
+		
 		/* Set the MySQL flag to mark that there is an active
 		transaction */
                 if (trx->active_trans == 0) {
@@ -6941,6 +6945,18 @@ ha_innobase::reset_auto_increment(ulonglong value)
 	DBUG_RETURN(0);
 }
 
+/* See comment in handler.cc */
+bool
+ha_innobase::get_error_message(int error, String *buf)
+{
+	trx_t*	    trx = check_trx_exists(current_thd);
+
+	buf->copy(trx->detailed_error, strlen(trx->detailed_error),
+		system_charset_info);
+
+	return FALSE;
+}
+
 /***********************************************************************
 Compares two 'refs'. A 'ref' is the (internal) primary key value of the row.
 If there is no explicitly declared non-null unique key or a primary key, then

sql/ha_innodb.h

@@ -175,6 +175,8 @@ class ha_innobase: public handler
 	ulonglong get_auto_increment();
 	int reset_auto_increment(ulonglong value);
 
+	virtual bool get_error_message(int error, String *buf);
+	
         uint8 table_cache_type() { return HA_CACHE_TBL_ASKTRANSACT; }
         /*
           ask handler about permission to cache table during query registration

sql/handler.cc

@@ -344,8 +344,8 @@ static int ha_init_errors(void)
   SETMSG(HA_ERR_READ_ONLY_TRANSACTION,  ER(ER_READ_ONLY_TRANSACTION));
   SETMSG(HA_ERR_LOCK_DEADLOCK,          ER(ER_LOCK_DEADLOCK));
   SETMSG(HA_ERR_CANNOT_ADD_FOREIGN,     ER(ER_CANNOT_ADD_FOREIGN));
-  SETMSG(HA_ERR_NO_REFERENCED_ROW,      ER(ER_NO_REFERENCED_ROW));
-  SETMSG(HA_ERR_ROW_IS_REFERENCED,      ER(ER_ROW_IS_REFERENCED));
+  SETMSG(HA_ERR_NO_REFERENCED_ROW,      ER(ER_NO_REFERENCED_ROW_2));
+  SETMSG(HA_ERR_ROW_IS_REFERENCED,      ER(ER_ROW_IS_REFERENCED_2));
   SETMSG(HA_ERR_NO_SAVEPOINT,           "No savepoint with that name");
   SETMSG(HA_ERR_NON_UNIQUE_BLOCK_SIZE,  "Non unique key block size");
   SETMSG(HA_ERR_NO_SUCH_TABLE,          "No such table: '%.64s'");
@@ -1798,11 +1798,19 @@ void handler::print_error(int error, myf errflag)
     textno=ER_CANNOT_ADD_FOREIGN;
     break;
   case HA_ERR_ROW_IS_REFERENCED:
-    textno=ER_ROW_IS_REFERENCED;
-    break;
+  {
+    String str;
+    get_error_message(error, &str);
+    my_error(ER_ROW_IS_REFERENCED_2, MYF(0), str.c_ptr_safe());
+    DBUG_VOID_RETURN;
+  }
   case HA_ERR_NO_REFERENCED_ROW:
-    textno=ER_NO_REFERENCED_ROW;
-    break;
+  {
+    String str;
+    get_error_message(error, &str);
+    my_error(ER_NO_REFERENCED_ROW_2, MYF(0), str.c_ptr_safe());
+    DBUG_VOID_RETURN;
+  }
   case HA_ERR_TABLE_DEF_CHANGED:
     textno=ER_TABLE_DEF_CHANGED;
     break;

sql/share/errmsg.txt

@@ -5415,3 +5415,7 @@ ER_NO_SUCH_USER
         eng "There is not %-.64s@%-.64s registered"
 ER_FORBID_SCHEMA_CHANGE
 	eng "Changing schema from '%-.64s' to '%-.64s' is not allowed."
+ER_ROW_IS_REFERENCED_2 23000
+	eng "Cannot delete or update a parent row: a foreign key constraint fails (%.192s)"
+ER_NO_REFERENCED_ROW_2 23000
+	eng "Cannot add or update a child row: a foreign key constraint fails (%.192s)"