select a.ID,a.NAME,b.MONEY from 表A a left join 表B b on a.ID=b.ID
declare @tb1 table(id char(10),name char(10)) declare @tb2 table (id char(10),money char(10)) insert @tb1 select '001', 'XXXX' union all select '002', 'YYYY' union all select '003', 'CCCC' insert @tb2 select '001','BBB' select a.id,a.name,b.money from @tb1 as a left join @tb2 as b on a.id = b.id /* 测试结果 id name money ---------- ---------- ---------- 001 XXXX BBB 002 YYYY NULL 003 CCCC NULL */
select a.id,a.name,b.money from a left join b on a.id=b.id
select a.ID,a.NAME,b.MONEY from 表A a,表B b where a.ID*=b.ID
select a.id,a.name,b.money from a left join b on a.id=b.id
select a.ID,a.NAME,b.MONEY from 表A a left join 表B b on a.ID=b.ID
declare @tb2 table (id char(10),money char(10))
insert @tb1
select '001', 'XXXX' union all
select '002', 'YYYY' union all
select '003', 'CCCC'
insert @tb2
select '001','BBB'
select a.id,a.name,b.money from @tb1 as a left join @tb2 as b on a.id = b.id
/*
测试结果
id name money
---------- ---------- ----------
001 XXXX BBB
002 YYYY NULL
003 CCCC NULL
*/