sql 常用临时表的区别(实例演示)
本文导语: sql 常用临时表的区别示例，供大家参考。 代码示例: --临时表，tempdb，手工删除 SELECT v.SONo,v.OrderNo,v.LogisticsCompanyCode,so.OrderId INTO #a FROM View_CourierReceipt v WITH(NOLOCK) LEFT JOIN ShippingOrder so WITH(NOLOCK) ON so.OrderN...
sql 常用临时表的区别示例，供大家参考。
--临时表，tempdb，手工删除
SELECT v.SONo,v.OrderNo,v.LogisticsCompanyCode,so.OrderId
INTO #a
FROM View_CourierReceipt v WITH(NOLOCK)
LEFT JOIN ShippingOrder so WITH(NOLOCK) ON so.OrderNo = v.OrderNo
WHERE v.CourierReceiptNo='EMS000000002'
select * from #a
select * from #a
drop table #a
--CTE，内存，自动删除
with a as(
SELECT v.SONo,v.OrderNo,v.LogisticsCompanyCode,so.OrderId
FROM View_CourierReceipt v WITH(NOLOCK)
LEFT JOIN ShippingOrder so WITH(NOLOCK) ON so.OrderNo = v.OrderNo
WHERE v.CourierReceiptNo='EMS000000002'
)
select * from a
select * from a --只能用一次a
--表变量，内存，自动删除
declare @a table(
[SONo] nvarchar(20)
,OrderNo nvarchar(20)
,LogisticsCompanyCode nvarchar(20)
,OrderId int
)
insert into @a
SELECT v.SONo,v.OrderNo,v.LogisticsCompanyCode,so.OrderId
FROM View_CourierReceipt v WITH(NOLOCK)
LEFT JOIN ShippingOrder so WITH(NOLOCK) ON so.OrderNo = v.OrderNo
WHERE v.CourierReceiptNo='EMS000000002'
select * from @a
select * from @a
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