我试过以下内容,但由于某种原因@check
参数设置为我试图检查的约束的值,即使约束不存在。如何检测是否在mysql存储过程中添加了外键?
任何想法为什么?
CREATE PROCEDURE AddForeignKey(
IN constraint_name varchar(64),
IN foreign_key_column_name varchar(64),
IN table_name varchar(64),
IN database_name varchar(64),
IN foreign_table_key_name varchar(64),
IN foreign_table_name varchar(64))
BEGIN
set @sql = CONCAT('ALTER TABLE ', database_name, '.', table_name,
' ADD CONSTRAINT ', constraint_name,
' FOREIGN KEY (', foreign_key_column_name, ')'
' REFERENCES ', foreign_table_name, ' (', foreign_table_key_name, ');') ;
set @dbname = database_name;
set @fkname = constraint_name;
set @check = '';
SELECT
CONSTRAINT_NAME
INTO
@check
FROM
INFORMATION_SCHEMA.TABLE_CONSTRAINTS
WHERE
CONSTRAINT_SCHEMA = @dbname
AND
CONSTRAINT_NAME = @fkname
AND
CONSTRAINT_TYPE = 'FOREIGN KEY'
LIMIT 1;
IF @check != @fkname
THEN
prepare stmt from @sql;
execute stmt;
ELSE
insert into errors(message) values (CONCAT ('Check: ', @check, ' DB:', @dbname, ' FK:', @fkname, ' Could not execute statement: ', @sql));
END IF;
END
我无法重现该问题。请参阅[db-fiddle](https://www.db-fiddle.com/f/huwJ99DrjLbaLPqKCvcBhB/0)。 – wchiquito
我没有使用MySQL作为root用户。我也使用MySQL 5.6。 – rstackhouse