这篇文章给大家介绍怎么在MySQL中动态更新数据库,内容非常详细,感兴趣的小伙伴们可以参考借鉴,希望对大家能有所帮助。
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动态删除索引
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;
动态添加字段
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;
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