假设我有以下简单的表变量:
declare @databases table
(
DatabaseID int,
Name varchar(15),
Server varchar(15)
)
-- insert a bunch rows into @databases
如果我想遍历各行,声明和使用游标是我唯一的选择吗?还有别的办法吗?
假设我有以下简单的表变量:
declare @databases table
(
DatabaseID int,
Name varchar(15),
Server varchar(15)
)
-- insert a bunch rows into @databases
如果我想遍历各行,声明和使用游标是我唯一的选择吗?还有别的办法吗?
当前回答
我将提供基于集合的解决方案。
insert @databases (DatabaseID, Name, Server)
select DatabaseID, Name, Server
From ... (Use whatever query you would have used in the loop or cursor)
这比任何循环技术都要快得多,而且更容易编写和维护。
其他回答
SELECT @pk = @pk + 1
会更好:
SET @pk += @pk
避免使用SELECT如果你没有引用表,只是分配值。
你可以使用while循环:
While (Select Count(*) From #TempTable) > 0
Begin
Insert Into @Databases...
Delete From #TempTable Where x = x
End
我将提供基于集合的解决方案。
insert @databases (DatabaseID, Name, Server)
select DatabaseID, Name, Server
From ... (Use whatever query you would have used in the loop or cursor)
这比任何循环技术都要快得多,而且更容易编写和维护。
-- [PO_RollBackOnReject] 'FININV10532'
alter procedure PO_RollBackOnReject
@CaseID nvarchar(100)
AS
Begin
SELECT *
INTO #tmpTable
FROM PO_InvoiceItems where CaseID = @CaseID
Declare @Id int
Declare @PO_No int
Declare @Current_Balance Money
While (Select ROW_NUMBER() OVER(ORDER BY PO_LineNo DESC) From #tmpTable) > 0
Begin
Select Top 1 @Id = PO_LineNo, @Current_Balance = Current_Balance,
@PO_No = PO_No
From #Temp
update PO_Details
Set Current_Balance = Current_Balance + @Current_Balance,
Previous_App_Amount= Previous_App_Amount + @Current_Balance,
Is_Processed = 0
Where PO_LineNumber = @Id
AND PO_No = @PO_No
update PO_InvoiceItems
Set IsVisible = 0,
Is_Processed= 0
,Is_InProgress = 0 ,
Is_Active = 0
Where PO_LineNo = @Id
AND PO_No = @PO_No
End
End
像这样定义临时表-
declare @databases table
(
RowID int not null identity(1,1) primary key,
DatabaseID int,
Name varchar(15),
Server varchar(15)
)
-- insert a bunch rows into @databases
然后这样做——
declare @i int
select @i = min(RowID) from @databases
declare @max int
select @max = max(RowID) from @databases
while @i <= @max begin
select DatabaseID, Name, Server from @database where RowID = @i --do some stuff
set @i = @i + 1
end