三条类似的SQL合并.怎么弄啊?

2012-06-12 11:29:06 216 阅读 AI 写同款 · GEO 优化AI 选题数据监测一键分发 ›

Excel用SQL合并多个工作表作者：iamlaosong 需求是统计全省各地市全年12个月的累计销售情况，原始数据是每个月一张明细表。简单的做法是合并12个月数据，做一个数据透视表就完成了。但同事不想合并12个月数据，因为那样每次数据变动都要合并一次。后来的做法是每个月做一个数据透视表（做好一个月后复制一份，改下数据源就可以完成另一个月）。然后再将已有月份的数据透视表中的数据求和。其实可以用SQL语句合并12各月份的数据（没有数据的月份做个带表头的空表），然后对这个合并的表做个数据透视表统计就可以了。这样每次数据变动时，只要刷新一阅读详情

首先.
数据库中有表A,B,C

表A中有一个字段name
表B中有一个字段name
表C中有一个字段name

我想查询foo这个在三个表中的name的字段里是否存在.

我是这么写的
select count(*) from A where A.name='foo'
select count(*) from B where B.name='foo'
select count(*) from C where C.name='foo'

这样的3条SQL我想可以合并成一个来查询.但是不知道怎么写好.

用不用count(*)都可以.只要能知道foo是否存在于三张表里就好.

如:在A.name中存在foo的话就返回1
都不存在就返回0

这样的形式...

求解.

...全文

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sqz10200

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切换为时间正序

以学习为目的 2012-06-16

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select  (case when (

        (SELECT COUNT(*) FROM A WHERE name='foo')=1  OR

        (SELECT COUNT(*) FROM B WHERE name='foo')=1  OR

        (SELECT COUNT(*) FROM C WHERE name='foo')=1) 

THEN '1 ' ELSE '0' END)

英児 2012-06-14

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if exists ( select 1 from A,B,C where A.name='foo' or b.name='foo' or c.name='foo')
begin
select '存在'
end
else
begin
select '不存在'
end

sqz10200 2012-06-13

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select sum(( select count(*) as A where A.name='foo')
+(select count(*) as B where B.name='foo')
+(select count(*) as C where C.name='foo')
) as s

我是这么写的

sqz10200 2012-06-12

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[Quote=引用 4 楼的回复:]

mssql:
SQL code
select top 1 case when (
(SELECT COUNT(*) FROM A WHERE name='foo')=1 OR
(SELECT COUNT(*) FROM B WHERE name='foo')=1 OR
(SELECT COUNT(*) FROM C WHERE name='……
[/Quote]

sysusers

啥意思啊.最后一句没看懂.

xxjltan 2012-06-12

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一条搞定试下这样

select A=(select count(*) from A where A.name='foo'),B=(select count(*) from B where B.name='foo'),C=(select count(*) from C where C.name='foo')

jornye 2012-06-12

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mssql:

select top 1 case when (

		(SELECT COUNT(*) FROM A WHERE name='foo')=1  OR

		(SELECT COUNT(*) FROM B WHERE name='foo')=1  OR

		(SELECT COUNT(*) FROM C WHERE name='foo')=1)

THEN '1 ' ELSE '0' END FROM sysusers

sqz10200 2012-06-12

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对了..
我的是mysql数据库.

天-笑 2012-06-12

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if exists(

		 select 1 as A where A.name='foo' UNION ALL

		 select 1 as B where B.name='foo' UNION ALL

		 select 1 as C where C.name='foo' 

)

begin

    print 'foo'

end

昵称被占用了 2012-06-12

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IF EXISTS (

select 1 from A where A.name='foo'

) OR EXISTS (

select 1 from B where B.name='foo'

) OR EXISTS (

select 1 from C where C.name='foo'

)

PRINT 1

ELSE

PEINR 0

wanghao2979 2012-06-12

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declare @tb_a table(name varchar(50))

declare @tb_b table(name varchar(50))

declare @tb_c table(name varchar(50))

insert into @tb_a(name) values('foo')

insert into @tb_b(name) values('foo')





select 1 from @tb_a where name = 'foo'

union 

select 1 from @tb_b where name = 'foo'

union 

select 1 from @tb_c where name = 'foo'

union all 改成 union

wanghao2979 2012-06-12

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declare @tb_a table(name varchar(50))
declare @tb_b table(name varchar(50))
declare @tb_c table(name varchar(50))
--insert into @tb_a(name) values('foo')

select 1 from @tb_a where name = 'foo'
union all
select 1 from @tb_b where name = 'foo'
union all
select 1 from @tb_c where name = 'foo'

孤独加百列 2012-06-12

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SELECT (select count(*) from A where A.name='foo') + (select count(*) from B where B.name='foo') + (select count(*) from C where C.name='foo')

sqz10200 2012-06-12

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不行啊.

jornye 2012-06-12

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mysql你可以这样查：

select  (case when (

		(SELECT COUNT(*) FROM A WHERE name='foo')=1  OR

		(SELECT COUNT(*) FROM B WHERE name='foo')=1  OR

		(SELECT COUNT(*) FROM C WHERE name='foo')=1) 

THEN '1 ' ELSE '0' END) as result

[Quote=引用 6 楼的回复:]
引用 4 楼的回复:

mssql:
SQL code
select top 1 case when (
(SELECT COUNT(*) FROM A WHERE name='foo')=1 OR
(SELECT COUNT(*) FROM B WHERE name='foo')=1 OR
(SELECT COUNT(*) FROM C WHERE name='……

s……
[/Quote]

三条类似的SQL合并.怎么弄啊?

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