今天小編為大家分享一篇關于Mysql動态更新資料庫腳本的示例講解，具體的upgrade腳本如下：
動态删除索引
DROP PROCEDURE IF EXISTS UPGRADE;DELIMITER $$CREATE PROCEDURE UPGRADE()BEGIN-- RESOURCE.AUDIO_ATTRIBUTE IF EXISTS(SELECT * FROM INFORMATION_SCHEMA.STATISTICS WHERE TABLE_SCHEMA = 'RESOURCE' AND TABLE_NAME = 'AUDIO_ATTRIBUTE' AND INDEX_NAME = 'resource_publish_resource_id_index') THEN ALTER TABLE `AUDIO_ATTRIBUTE` DROP INDEX resource_publish_resource_id_index; END IF;END$$DELIMITER ;CALL UPGRADE();DROP PROCEDURE IF EXISTS UPGRADE;
動态添加字段
DROP PROCEDURE IF EXISTS UPGRADE;DELIMITER $$CREATE PROCEDURE UPGRADE()BEGIN-- HOMEWORK.HOMEWORK_QUESTION_GROUP.FROM_ID IF NOT EXISTS(SELECT * FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_SCHEMA = 'HOMEWORK' AND TABLE_NAME = 'HOMEWORK_QUESTION_GROUP' AND COLUMN_NAME = 'FROM_ID') THEN ALTER TABLE `HOMEWORK_QUESTION_GROUP` ADD COLUMN FROM_ID VARCHAR(50) NULL; END IF;-- HOMEWORK.HOMEWORK_QUESTION_GROUP.QUESTION_TYPE IF NOT EXISTS(SELECT * FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_SCHEMA = 'HOMEWORK' AND TABLE_NAME = 'HOMEWORK_QUESTION_GROUP' AND COLUMN_NAME = 'QUESTION_TYPE') THEN ALTER TABLE `HOMEWORK_QUESTION_GROUP` ADD COLUMN QUESTION_TYPE VARCHAR(50) NULL; END IF;-- HOMEWORK.HOMEWORK_QUESTION_GROUP.DIFFICULTY IF NOT EXISTS(SELECT * FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_SCHEMA = 'HOMEWORK' AND TABLE_NAME = 'HOMEWORK_QUESTION_GROUP' AND COLUMN_NAME = 'DIFFICULTY') THEN ALTER TABLE `HOMEWORK_QUESTION_GROUP` ADD COLUMN DIFFICULTY VARCHAR(50) NULL; END IF;END$$DELIMITER ;CALL UPGRADE();DROP PROCEDURE IF EXISTS UPGRADE;
其他文法類似，主要區分EXISTS和NOT EXISTS的用法。
以上就是本文的全部内容，希望對大家的學習有所幫助，如果大家有任何疑問請給我留言，小編會及時回複大家的。後面小編會分享更多運維方面的幹貨，感興趣的朋友走一波關注哩~
