饿虎岗资源网 Design By www.oxmxm.com

具体的upgrade脚本如下:

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;

其他语法类似,主要区分EXISTSNOT EXISTS的用法。 

总结

以上就是这篇文章的全部内容了,希望本文的内容对大家的学习或者工作具有一定的参考学习价值,谢谢大家对的支持。如果你想了解更多相关内容请查看下面相关链接

饿虎岗资源网 Design By www.oxmxm.com
广告合作:本站广告合作请联系QQ:858582 申请时备注:广告合作(否则不回)
免责声明:本站资源来自互联网收集,仅供用于学习和交流,请遵循相关法律法规,本站一切资源不代表本站立场,如有侵权、后门、不妥请联系本站删除!
饿虎岗资源网 Design By www.oxmxm.com