select t1.id,t1.value-isnull(t2.value,0)-isnull(t3.value,0) value from t1 left join t2 on t1.id=t2.id left join t3 on t1.id=t3.id
select id,sum(value) from ( select id,value from t1 union all select id,-value from t2 union all select id,-value from t3) tem group by id
select t1.id,t1.value-isnull(t2.value,0)-isnull(t3.value,0) as value from t1 left join t2 on t1.id=t2.id left join t3 on t1.id=t3.id
select isnull(isnull(t1.id,t2.id),t3.id) id,isnull(t1.value,0)-isnull(t2.value,0)-isnull(t3.value,0) value from t1 full join t2 on t1.id=t2.id full join t3 on t1.id=t3.id这两个都可以应付id只存在与任何一个表中的情况。
各位DX,在提交新记录到远程SQL SERVER时(通过表单提交,非SQL语句),提示出错Unable to start a nested transaction for OLE DB provider 'SQLOLEDB'. A nested transaction was required because the XACT_ABORT option was set to OFF. (SQL Server 7395),如何解决?谢谢
left join t2 on t1.id=t2.id
left join t3 on t1.id=t3.id
select id,value from t1
union all
select id,-value from t2
union all
select id,-value from t3) tem group by id
from t1
left join t2 on t1.id=t2.id
left join t3 on t1.id=t3.id
full join t2 on t1.id=t2.id
full join t3 on t1.id=t3.id这两个都可以应付id只存在与任何一个表中的情况。
我现在没有sqlserver,在access2000试了试
access2000似乎不可以用2个left join?access不应该这么傻吧?
而且access必须写成iif(isnull(的形式
那不是不能和sqlserver混用了?我这个程序有2个数据库,一个是sqlserver,一个是access,怎么办?
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既然不需要null结果,就不应该使用left join,应该用inner join。
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既然不需要null结果,就不应该使用left join,应该用inner join。