MySql存储过程批量删除多个数据库中同名表中的指定字段

时间:2021-11-11 08:36:03

1、 创建存储过程batchDeleteField:删除所有名称为"MyDB_"开头的数据库中的指定字段

-- ----------------------------
-- Procedure structure for batchDeleteField
-- ----------------------------
DROP PROCEDURE IF EXISTS `batchDeleteField`;
DELIMITER ;;
CREATE DEFINER=`root`@`%` PROCEDURE `batchDeleteField`(IN `tableName` varchar(100),IN `fieldName` varchar(100))
BEGIN
#数据库名称
DECLARE schemaName VARCHAR(100); #声明结束标识
DECLARE end_flag int DEFAULT 0;
#声明游标 curosr ,查找所有“MyDB_”开头的数据库
DECLARE curosr CURSOR FOR select TABLE_SCHEMA from information_schema.`TABLES` WHERE TABLE_SCHEMA like 'MyDB_%' and table_name = tableName;
#设置终止标志
DECLARE CONTINUE HANDLER FOR NOT FOUND SET end_flag=1; #打开游标
OPEN curosr; #遍历游标
loop_label: LOOP FETCH curosr INTO schemaName;#获取当前游标指针记录,取出值赋给自定义的变量 IF end_flag > 0 THEN
LEAVE loop_label;
END IF; SET @sqlStr=CONCAT('alter table ',schemaName,'.',tableName,' drop column `',fieldName,'` ');
PREPARE stmt from @sqlStr;
EXECUTE stmt; END LOOP; #关闭游标
close curosr;
END
;;
DELIMITER ;

2、调用存储过程:

batchDeleteField('Users','score') //删除Users表中的score字段