MDEV-8524: Improve error messaging when there is duplicate key or foreign key names

Added better error message that will be printed when foreign key
constraint name in create table is not unique in database.

mysql-test/suite/innodb/r/innodb-fk-warnings.result

+CREATE TABLE t1 (
+id int(11) NOT NULL PRIMARY KEY,
+a int(11) NOT NULL,
+b int(11) NOT NULL,
+c int not null,
+CONSTRAINT test FOREIGN KEY (b) REFERENCES t1 (id)
+) ENGINE=InnoDB DEFAULT CHARSET=latin1;
+CREATE TABLE t2 (
+id int(11) NOT NULL PRIMARY KEY,
+a int(11) NOT NULL,
+b int(11) NOT NULL,
+c int not null,
+CONSTRAINT test FOREIGN KEY (b) REFERENCES t2 (id)
+) ENGINE=InnoDB DEFAULT CHARSET=latin1;
+ERROR HY000: Can't create table 'test.t2' (errno: 121)
+show warnings;
+Level	Code	Message
+Warning	121	InnoDB: foreign key constraint name `test/test` already exists on data dictionary. Foreign key constraint names need to be unique in database. Error in foreign key definition: CONSTRAINT `test` FOREIGN KEY (`b`) REFERENCES `test`.`t2` (`id`).
+Error	1005	Can't create table 'test.t2' (errno: 121)
+drop table t1;

mysql-test/suite/innodb/t/innodb-fk-warnings.test

+--source include/have_innodb.inc
+
+#
+# MDEV-8524: Improve error messaging when there is duplicate key or foreign key names
+#
+CREATE TABLE t1 (
+  id int(11) NOT NULL PRIMARY KEY,
+  a int(11) NOT NULL,
+  b int(11) NOT NULL,
+  c int not null,
+  CONSTRAINT test FOREIGN KEY (b) REFERENCES t1 (id)
+) ENGINE=InnoDB DEFAULT CHARSET=latin1;
+
+#
+# Below create table fails because constraint name test
+# is reserved for above table.
+#
+--error 1005
+CREATE TABLE t2 (
+  id int(11) NOT NULL PRIMARY KEY,
+  a int(11) NOT NULL,
+  b int(11) NOT NULL,
+  c int not null,
+  CONSTRAINT test FOREIGN KEY (b) REFERENCES t2 (id)
+) ENGINE=InnoDB DEFAULT CHARSET=latin1;
+
+show warnings;
+
+drop table t1;

storage/innobase/dict/dict0crea.c

@@ -1419,6 +1419,91 @@ dict_create_add_foreign_field_to_dictionary(
 		       table, foreign, trx));
 }
 
+/********************************************************************//**
+Construct foreign key constraint defintion from data dictionary information.
+*/
+static
+char*
+dict_foreign_def_get(
+	dict_foreign_t*	foreign,/*!< in: foreign */
+	trx_t*		trx)	/*!< in: trx */
+{
+	char* fk_def = mem_heap_alloc(foreign->heap, 4*1024);
+	const char* tbname;
+	char tablebuf[MAX_TABLE_NAME_LEN + 1] = "";
+	int i;
+
+	tbname = dict_remove_db_name(foreign->id);
+	innobase_convert_name(tablebuf, MAX_TABLE_NAME_LEN,
+				tbname, strlen(tbname), trx->mysql_thd, FALSE);
+
+	sprintf(fk_def,
+		(char *)"CONSTRAINT %s FOREIGN KEY (", (char *)tablebuf);
+
+	for(i = 0; i < foreign->n_fields; i++) {
+		char	buf[MAX_TABLE_NAME_LEN + 1] = "";
+		innobase_convert_name(buf, MAX_TABLE_NAME_LEN,
+				foreign->foreign_col_names[i],
+				strlen(foreign->foreign_col_names[i]),
+				trx->mysql_thd, FALSE);
+		strcat(fk_def, buf);
+		if (i < foreign->n_fields-1) {
+			strcat(fk_def, (char *)",");
+		}
+	}
+
+	strcat(fk_def,(char *)") REFERENCES ");
+
+	innobase_convert_name(tablebuf, MAX_TABLE_NAME_LEN,
+	        foreign->referenced_table_name,
+		strlen(foreign->referenced_table_name),
+		trx->mysql_thd, TRUE);
+
+	strcat(fk_def, tablebuf);
+	strcat(fk_def, " (");
+
+	for(i = 0; i < foreign->n_fields; i++) {
+		char	buf[MAX_TABLE_NAME_LEN + 1] = "";
+		innobase_convert_name(buf, MAX_TABLE_NAME_LEN,
+				foreign->referenced_col_names[i],
+				strlen(foreign->referenced_col_names[i]),
+				trx->mysql_thd, FALSE);
+		strcat(fk_def, buf);
+		if (i < foreign->n_fields-1) {
+			strcat(fk_def, (char *)",");
+		}
+	}
+	strcat(fk_def, (char *)")");
+
+	return fk_def;
+}
+
+/********************************************************************//**
+Convert foreign key column names from data dictionary to SQL-layer.
+*/
+static
+void
+dict_foreign_def_get_fields(
+	dict_foreign_t*	foreign,/*!< in: foreign */
+	trx_t*		trx,	/*!< in: trx */
+	char**		field,  /*!< out: foreign column */
+	char**		field2, /*!< out: referenced column */
+	int		col_no) /*!< in: column number */
+{
+	*field = mem_heap_alloc(foreign->heap, MAX_TABLE_NAME_LEN+1);
+	*field2 = mem_heap_alloc(foreign->heap, MAX_TABLE_NAME_LEN+1);
+
+	innobase_convert_name(*field, MAX_TABLE_NAME_LEN,
+		foreign->foreign_col_names[col_no],
+		strlen(foreign->foreign_col_names[col_no]),
+		trx->mysql_thd, FALSE);
+
+	innobase_convert_name(*field, MAX_TABLE_NAME_LEN,
+		foreign->referenced_col_names[col_no],
+		strlen(foreign->referenced_col_names[col_no]),
+		trx->mysql_thd, FALSE);
+}
+
 /********************************************************************//**
 Add a single foreign key definition to the data dictionary tables in the
 database. We also generate names to constraints that were not named by the
@@ -1501,6 +1586,22 @@ dict_create_add_foreign_to_dictionary(
 
 	if (error != DB_SUCCESS) {
 
+		if (error == DB_DUPLICATE_KEY) {
+			char	buf[MAX_TABLE_NAME_LEN + 1] = "";
+			char*	fk_def;
+
+			innobase_convert_name(buf, MAX_TABLE_NAME_LEN,
+				foreign->id, strlen(foreign->id), trx->mysql_thd, FALSE);
+
+			fk_def = dict_foreign_def_get(foreign, trx);
+
+			ib_push_warning(trx, error, (const char *)"InnoDB: foreign key constraint name %s "
+				"already exists on data dictionary."
+				" Foreign key constraint names need to be unique in database."
+				" Error in foreign key definition: %s.",
+				buf, fk_def);
+		}
+
 		return(error);
 	}
 
@@ -1509,6 +1610,20 @@ dict_create_add_foreign_to_dictionary(
 			i, table, foreign, trx);
 
 		if (error != DB_SUCCESS) {
+			char	buf[MAX_TABLE_NAME_LEN + 1] = "";
+			char*	field=NULL;
+			char*	field2=NULL;
+			char*	fk_def;
+
+			innobase_convert_name(buf, MAX_TABLE_NAME_LEN,
+				foreign->id, strlen(foreign->id), trx->mysql_thd, FALSE);
+			fk_def = dict_foreign_def_get(foreign, trx);
+			dict_foreign_def_get_fields(foreign, trx, &field, &field2, i);
+
+			ib_push_warning(trx, error,
+				(const char *)"InnoDB: Error adding foreign  key constraint name %s fields %s or %s to the dictionary."
+				" Error in foreign key definition: %s.",
+				buf, i+1, fk_def);
 
 			return(error);
 		}

storage/innobase/handler/ha_innodb.cc

@@ -12304,3 +12304,29 @@ ib_warn_row_too_big(const dict_table_t*	table)
 		" ROW_FORMAT=COMPRESSED ": ""
 		, prefix ? DICT_MAX_FIXED_COL_LEN : 0);
 }
+
+/********************************************************************//**
+Helper function to push warnings from InnoDB internals to SQL-layer. */
+extern "C" UNIV_INTERN
+void
+ib_push_warning(
+	trx_t*		trx,	/*!< in: trx */
+	ulint		error,	/*!< in: error code to push as warning */
+	const char	*format,/*!< in: warning message */
+	...)
+{
+	va_list args;
+	THD *thd = (THD *)trx->mysql_thd;
+	char *buf;
+#define MAX_BUF_SIZE 4*1024
+
+	va_start(args, format);
+	buf = (char *)my_malloc(MAX_BUF_SIZE, MYF(MY_WME));
+	vsprintf(buf,format, args);
+
+	push_warning_printf(thd, MYSQL_ERROR::WARN_LEVEL_WARN,
+		convert_error_code_to_mysql(error, 0, thd),
+		buf);
+	my_free(buf);
+	va_end(args);
+}

storage/innobase/include/ha_prototypes.h

@@ -326,5 +326,14 @@ innobase_convert_to_filename_charset(
 	const char*     from,   /* in: identifier to convert */
 	ulint           len);   /* in: length of 'to', in bytes */
 
+/********************************************************************//**
+Helper function to push warnings from InnoDB internals to SQL-layer. */
+UNIV_INTERN
+void
+ib_push_warning(
+	trx_t*		trx,	/*!< in: trx */
+	ulint		error,	/*!< in: error code to push as warning */
+	const char	*format,/*!< in: warning message */
+	...);
 
 #endif

storage/xtradb/dict/dict0crea.c

@@ -1626,6 +1626,91 @@ dict_create_add_foreign_field_to_dictionary(
 		       table, foreign, trx));
 }
 
+/********************************************************************//**
+Construct foreign key constraint defintion from data dictionary information.
+*/
+static
+char*
+dict_foreign_def_get(
+	dict_foreign_t*	foreign,/*!< in: foreign */
+	trx_t*		trx)	/*!< in: trx */
+{
+	char* fk_def = mem_heap_alloc(foreign->heap, 4*1024);
+	const char* tbname;
+	char tablebuf[MAX_TABLE_NAME_LEN + 1] = "";
+	int i;
+
+	tbname = dict_remove_db_name(foreign->id);
+	innobase_convert_name(tablebuf, MAX_TABLE_NAME_LEN,
+				tbname, strlen(tbname), trx->mysql_thd, FALSE);
+
+	sprintf(fk_def,
+		(char *)"CONSTRAINT %s FOREIGN KEY (", (char *)tablebuf);
+
+	for(i = 0; i < foreign->n_fields; i++) {
+		char	buf[MAX_TABLE_NAME_LEN + 1] = "";
+		innobase_convert_name(buf, MAX_TABLE_NAME_LEN,
+				foreign->foreign_col_names[i],
+				strlen(foreign->foreign_col_names[i]),
+				trx->mysql_thd, FALSE);
+		strcat(fk_def, buf);
+		if (i < foreign->n_fields-1) {
+			strcat(fk_def, (char *)",");
+		}
+	}
+
+	strcat(fk_def,(char *)") REFERENCES ");
+
+	innobase_convert_name(tablebuf, MAX_TABLE_NAME_LEN,
+	        foreign->referenced_table_name,
+		strlen(foreign->referenced_table_name),
+		trx->mysql_thd, TRUE);
+
+	strcat(fk_def, tablebuf);
+	strcat(fk_def, " (");
+
+	for(i = 0; i < foreign->n_fields; i++) {
+		char	buf[MAX_TABLE_NAME_LEN + 1] = "";
+		innobase_convert_name(buf, MAX_TABLE_NAME_LEN,
+				foreign->referenced_col_names[i],
+				strlen(foreign->referenced_col_names[i]),
+				trx->mysql_thd, FALSE);
+		strcat(fk_def, buf);
+		if (i < foreign->n_fields-1) {
+			strcat(fk_def, (char *)",");
+		}
+	}
+	strcat(fk_def, (char *)")");
+
+	return fk_def;
+}
+
+/********************************************************************//**
+Convert foreign key column names from data dictionary to SQL-layer.
+*/
+static
+void
+dict_foreign_def_get_fields(
+	dict_foreign_t*	foreign,/*!< in: foreign */
+	trx_t*		trx,	/*!< in: trx */
+	char**		field,  /*!< out: foreign column */
+	char**		field2, /*!< out: referenced column */
+	int		col_no) /*!< in: column number */
+{
+	*field = mem_heap_alloc(foreign->heap, MAX_TABLE_NAME_LEN+1);
+	*field2 = mem_heap_alloc(foreign->heap, MAX_TABLE_NAME_LEN+1);
+
+	innobase_convert_name(*field, MAX_TABLE_NAME_LEN,
+		foreign->foreign_col_names[col_no],
+		strlen(foreign->foreign_col_names[col_no]),
+		trx->mysql_thd, FALSE);
+
+	innobase_convert_name(*field, MAX_TABLE_NAME_LEN,
+		foreign->referenced_col_names[col_no],
+		strlen(foreign->referenced_col_names[col_no]),
+		trx->mysql_thd, FALSE);
+}
+
 /********************************************************************//**
 Add a single foreign key definition to the data dictionary tables in the
 database. We also generate names to constraints that were not named by the
@@ -1708,6 +1793,22 @@ dict_create_add_foreign_to_dictionary(
 
 	if (error != DB_SUCCESS) {
 
+		if (error == DB_DUPLICATE_KEY) {
+			char	buf[MAX_TABLE_NAME_LEN + 1] = "";
+			char*	fk_def;
+
+			innobase_convert_name(buf, MAX_TABLE_NAME_LEN,
+				foreign->id, strlen(foreign->id), trx->mysql_thd, FALSE);
+
+			fk_def = dict_foreign_def_get(foreign, trx);
+
+			ib_push_warning(trx, error, (const char *)"InnoDB: foreign key constraint name %s "
+				"already exists on data dictionary."
+				" Foreign key constraint names need to be unique in database."
+				" Error in foreign key definition: %s.",
+				buf, fk_def);
+		}
+
 		return(error);
 	}
 
@@ -1716,6 +1817,20 @@ dict_create_add_foreign_to_dictionary(
 			i, table, foreign, trx);
 
 		if (error != DB_SUCCESS) {
+			char	buf[MAX_TABLE_NAME_LEN + 1] = "";
+			char*	field=NULL;
+			char*	field2=NULL;
+			char*	fk_def;
+
+			innobase_convert_name(buf, MAX_TABLE_NAME_LEN,
+				foreign->id, strlen(foreign->id), trx->mysql_thd, FALSE);
+			fk_def = dict_foreign_def_get(foreign, trx);
+			dict_foreign_def_get_fields(foreign, trx, &field, &field2, i);
+
+			ib_push_warning(trx, error,
+				(const char *)"InnoDB: Error adding foreign  key constraint name %s fields %s or %s to the dictionary."
+				" Error in foreign key definition: %s.",
+				buf, i+1, fk_def);
 
 			return(error);
 		}

storage/xtradb/handler/ha_innodb.cc

@@ -14107,3 +14107,28 @@ ha_innobase::idx_cond_push(
 	DBUG_RETURN(NULL);
 }
 
+/********************************************************************//**
+Helper function to push warnings from InnoDB internals to SQL-layer. */
+extern "C" UNIV_INTERN
+void
+ib_push_warning(
+	trx_t*		trx,	/*!< in: trx */
+	ulint		error,	/*!< in: error code to push as warning */
+	const char	*format,/*!< in: warning message */
+	...)
+{
+	va_list args;
+	THD *thd = (THD *)trx->mysql_thd;
+	char *buf;
+#define MAX_BUF_SIZE 4*1024
+
+	va_start(args, format);
+	buf = (char *)my_malloc(MAX_BUF_SIZE, MYF(MY_WME));
+	vsprintf(buf,format, args);
+
+	push_warning_printf(thd, MYSQL_ERROR::WARN_LEVEL_WARN,
+		convert_error_code_to_mysql(error, 0, thd),
+		buf);
+	my_free(buf);
+	va_end(args);
+}

storage/xtradb/include/ha_prototypes.h

@@ -353,5 +353,14 @@ innobase_convert_to_filename_charset(
 	const char*     from,   /* in: identifier to convert */
 	ulint           len);   /* in: length of 'to', in bytes */
 
+/********************************************************************//**
+Helper function to push warnings from InnoDB internals to SQL-layer. */
+UNIV_INTERN
+void
+ib_push_warning(
+	trx_t*		trx,	/*!< in: trx */
+	ulint		error,	/*!< in: error code to push as warning */
+	const char	*format,/*!< in: warning message */
+	...);
 
 #endif