好的。简而言之,我正在尝试执行INSERT SELECT,例如:
START TRANSACTION; INSERT INTO dbNEW.entity (commonName, surname) SELECT namefirst, namelast FROM dbOLD.user; SET @key = LAST_INSERT_ID(); INSERT INTO dbNEW.user (userID, entityID, other) SELECT user_id, @key, other FROM dbOLD.user; COMMIT;
当然,@key不会从每个插入中返回每个后续的LAST_INSERT_ID(),而是仅从最后一个插入返回ID。
基本上,我将旧的USER表拆分为ENTITY和USER,例如:
dbOLD.user +-------------+---------------------+------+-----+------------+----------------+ | Field | Type | Null | Key | Default | Extra | +-------------+---------------------+------+-----+------------+----------------+ | user_id | int(10) unsigned | NO | PRI | NULL | auto_increment | | namefirst | varchar(20) | NO | | | | | namelast | varchar(20) | NO | | | | | other | varchar(10) | NO | | | | +-------------+---------------------+------+-----+------------+----------------+ dbNEW.user +-------------+---------------------+------+-----+------------+----------------+ | Field | Type | Null | Key | Default | Extra | +-------------+---------------------+------+-----+------------+----------------+ | userID | int(10) unsigned | NO | PRI | NULL | auto_increment | | entityID | int(10) unsigned | NO | MUL | 0 | | | other | varchar(10) | NO | | | | +-------------+---------------------+------+-----+------------+----------------+ dbNEW.entity +--------------+---------------------+------+-----+------------+----------------+ | Field | Type | Null | Key | Default | Extra | +--------------+---------------------+------+-----+------------+----------------+ | entityID | int(10) unsigned | NO | PRI | NULL | auto_increment | | commonName | varchar(20) | NO | | | | | surname | varchar(20) | NO | | | | +--------------+---------------------+------+-----+------------+----------------+
我为什么要这样做?基本上,我有一个“商店”实体,它将具有“用户”公用的字段,例如地址和电话号码。因此,任何“ ENTITY”都可能没有多个地址(送货,帐单,邮寄),也没有多个电话号码(传真,主,帐单,手机,家),可能有其他方法可以做到这一点,但这是我的解决方案最后。
旧数据库中的商店和用户需要保留其旧PK,并获得额外的ENTITY fk。如何在不进行转储和手动编辑的情况下执行此操作?
对于最后一个查询,请使用此
INSERT INTO dbNEW.`user` (userID, entityID, other) SELECT user_id, entityID, other FROM ( SELECT user_id, @key + @rn entityID, other, @rn := @rn + 1 FROM (select @rn:=0) x, dbOLD.`user` order by user_id ) y;
MySQL中的LAST_INSERT_ID()是成批创建的第一个ID,与SQL Server中的SCOPE_IDENTITY()不同,后者是LAST ID。由于它是第一行,因此我们使用变量@rn从addition=0第一行开始递增每一行。
addition=0