Comments on: 节约数据迁移??分钟

By: jametong

jametong — Sun, 12 Oct 2008 18:40:18 +0000

上面的逻辑修改还是有问题吧..
CREATE TABLE A_1
SELECT A.* FROM A
WHERE A.ID IN (SELECT ID FROM B)
WHERE A.ID IN (SELECT ID FROM C)
WHERE A.ID IN (SELECT ID FROM D)
WHERE A.ID IN (SELECT ID FROM E)
有两种修改方法.
1. 改成in 一个表.
CREATE TABLE A_1
SELECT A.* FROM A
WHERE A.ID in (
select id from b
union all
select id from c
union all
select id from d
union all
select id from e
);
2. 改成普通表连接.
CREATE TABLE A_1
SELECT A.*
FROM A, (
select distinct id from b
union
select distinct id from c
union
select distinct id from d
union
select distinct id from e
) TX
WHERE A.ID = TX.id

By: anysql

anysql — Thu, 17 Jul 2008 06:11:46 +0000

谢谢指正，已修改。

By: alpha.cao

alpha.cao — Thu, 17 Jul 2008 06:01:56 +0000

CREATE TABLE A_1
SELECT A.* FROM A,B,C,D,E
WHERE A.ID IN (SELECT ID FROM B)
WHERE A.ID IN (SELECT ID FROM C)
WHERE A.ID IN (SELECT ID FROM D)
WHERE A.ID IN (SELECT ID FROM E)
可以这样写吗？
是不是这样的：
CREATE TABLE A_1
SELECT A.* FROM A
WHERE A.ID IN (SELECT ID FROM B)
and A.ID IN (SELECT ID FROM C)
and A.ID IN (SELECT ID FROM D)
and A.ID IN (SELECT ID FROM E)

By: alpha.cao

alpha.cao — Thu, 17 Jul 2008 05:42:20 +0000

不错，要是把2者的执行计划贴出来，我们菜鸟看起来就方便了！

By: niubro

niubro — Sat, 12 Jul 2008 05:10:42 +0000

这几篇文章都是迁移数据的，不错，学习了，能不能整理一个通用的