当我没有使用 out 变量时,存储过程可以正常工作,但是当我执行没有 out 变量的存储过程时,会出现此错误:
MySQL said: #1327 - Undeclared variable: sp_result
代码:
CREATE DEFINER=`root`@`localhost` PROCEDURE `test3`(OUT `sp_result` INT(11), IN `sp_where_param` VARCHAR(100), IN `sp_where_value` VARCHAR(100), IN `sp_table_name` VARCHAR(100))
NO SQL
BEGIN
DECLARE tbl_id VARCHAR(100);
SET tbl_id = CONCAT(sp_table_name,'_id');
SET @temp1=CONCAT('SELECT count(',tbl_id,') INTO sp_result FROM ',sp_table_name,' WHERE ',sp_where_param,' = \'',sp_where_value,'\'');
PREPARE stmt1 FROM @temp1;
EXECUTE stmt1;
END
也许没有 out 变量也不起作用:(
最佳答案
尝试使用用户变量 -
CREATE DEFINER = 'root'@'localhost'
PROCEDURE test3 (OUT `sp_result` int(11), IN `sp_where_param` varchar(100), IN `sp_where_value` varchar(100), IN `sp_table_name` varchar(100))
NO SQL
BEGIN
DECLARE tbl_id varchar(100);
SET tbl_id = CONCAT(sp_table_name, '_id');
SET @temp1 = CONCAT('SELECT COUNT(', tbl_id, ') INTO @sp_result FROM ', sp_table_name, ' WHERE ', sp_where_param, ' = \'', sp_where_value, '\'');
PREPARE stmt1 FROM @temp1;
EXECUTE stmt1;
DEALLOCATE PREPARE stmt1;
set sp_result = @sp_result;
END
...并添加 DEALLOCATE PREPARE 语句。
关于Mysql存储过程动态选择不带out变量,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/14050423/