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[数据库]mysql 判断表字段或索引是否存在


判断字段是否存在:

1 DROP PROCEDURE IF EXISTS schema_change;  2 DELIMITER // 3 CREATE PROCEDURE schema_change() BEGIN 4 DECLARE CurrentDatabase VARCHAR(100); 5 SELECT DATABASE() INTO CurrentDatabase; 6 IF NOT EXISTS (SELECT * FROM information_schema.columns WHERE table_schema=CurrentDatabase AND table_name = 'rtc_order' AND column_name = 'IfUpSend') THEN  7   ALTER TABLE rtc_order 8   ADD COLUMN `IfUpSend` BIT NOT NULL DEFAULT 0 COMMENT '是否上传 是否上传'; 9 END IF; 10 END// 11 DELIMITER ; 12 CALL schema_change();

判断索引是否存在:

 1 DROP PROCEDURE IF EXISTS schema_change;  2 DELIMITER // 3 CREATE PROCEDURE schema_change() BEGIN 4 DECLARE CurrentDatabase VARCHAR(100); 5 SELECT DATABASE() INTO CurrentDatabase; 6 IF NOT EXISTS (SELECT * FROM information_schema.statistics WHERE table_schema=CurrentDatabase AND table_name = 'rtc_phototype' AND index_name = 'index_name') THEN  7  ALTER TABLE `rtc_Phototype` ADD INDEX index_name ( `imgtype` ); 8 END IF;  9 END// 10 DELIMITER ; 11 CALL schema_change(); 

从这两段可以看出很多东西,具体可以自己试验一下