Submit My Question - Recent Questions - Recent Answer
Msdn China Tech >> Delphi >> VCL组件开发及应用

不知能否用SQL语句实现?

我有两个表Table1,Table2,字段相同，
Table1:
Field1 Field2
a1 b1
a2 b2
a3 b3
Table2:
Field1 Field2
a1 b1
a2 b1
a3 b3
表1 的纪录是没有重复的，而表2的纪录是有重复的
现在我想用一条SQL语句取得这两个表中Field2的值等于b1的纪录,应该怎样写呢？
[260 byte] By [hansonboy-hansonboy] at [2008-2-13]
«« javascript的中文问题
»» 有关delphi开发数据库com的简单问题,送分!
# 1
up.
hansonboy-hansonboy at 2007-10-22 > top of Msdn China Tech,Delphi,VCL组件开发及应用...
# 2
先单独查询，然后合起来!
wy1086-楼主 at 2007-10-22 > top of Msdn China Tech,Delphi,VCL组件开发及应用...
# 3
select field1,field2 from table1 where field2='b1'
union
select field1,field2 from table2 where field2='b1'
chen_yj-今天 at 2007-10-22 > top of Msdn China Tech,Delphi,VCL组件开发及应用...
# 4
看这样行不行
//*******************************************
select field1,field2 from table1 where field2='b1'
union all
select field1,field2 from table2 where field2='b1'
//******************************************
这样所有重复的纪录也都取出来了，试一下
fwjingling-蓝精灵 at 2007-10-22 > top of Msdn China Tech,Delphi,VCL组件开发及应用...
# 5
如果是SQL server7:
select field1,field2 from table1 a left join table2 b on a.field2 = b.field2
where a.fieid2='b1'
huojiehai-海天子 at 2007-10-22 > top of Msdn China Tech,Delphi,VCL组件开发及应用...
Delphi
VCL组件开发及应用

Delphi Hot Topic

Delphi New Topic

Delphi

Java / MSDN / Linux Tech / PHP Tech / MSDN DotNet / MSDN TECH / Health Library / Programmers Tech / visual basic Tech / Developer Tech / Ipod faqs / Msdn China Tech

Site Classified