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這篇文章給大家介紹怎么在 Mysql 中動態更新數據庫,內容非常詳細,感興趣的小伙伴們可以參考借鑒,希望對大家能有所幫助。
動態刪除索引
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;
動態添加字段
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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