232

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();