T-SQL循环查询结果

Question

我运行一个查询select @id=table.id from table,我需要循环结果,所以我可以执行每行的存储过程exec stored_proc @varName=@id,@otherVarName='test'

如何在T-SQL脚本中执行此操作？

Answer 1

在这种情况下你可以使用CURSOR:

DECLARE @id INT
DECLARE @name NVARCHAR(100)
DECLARE @getid CURSOR

SET @getid = CURSOR FOR
SELECT table.id,
       table.name
FROM   table

OPEN @getid
FETCH NEXT
FROM @getid INTO @id, @name
WHILE @@FETCH_STATUS = 0
BEGIN
    EXEC stored_proc @varName=@id, @otherVarName='test', @varForName=@name
    FETCH NEXT
    FROM @getid INTO @id, @name
END

CLOSE @getid
DEALLOCATE @getid

修改为显示表中的多个参数.

Answer 2

你可以这样做:

create procedure test
as
BEGIN

    create table #ids
    (
        rn int,
        id int
    )

    insert into #ids (rn, id)
    select distinct row_number() over(order by id) as rn, id
    from table

    declare @id int
    declare @totalrows int = (select count(*) from #ids)
    declare @currentrow int = 0

    while @currentrow <  @totalrows  
    begin 
        set @id = (select id from #ids where rn = @currentrow)

        exec stored_proc @varName=@id, @otherVarName='test'

        set @currentrow = @currentrow +1
    end  

END

Answer 3

我更喜欢的解决方案是Microsoft KB 111401 http://support.microsoft.com/kb/111401.

该链接指的是3个例子:

本文介绍了可用于在存储过程,触发器或Transact-SQL批处理中模拟类似游标的FETCH-NEXT逻辑的各种方法.

/*********** example 1 ***********/ 

declare @au_id char( 11 )

set rowcount 0
select * into #mytemp from authors

set rowcount 1

select @au_id = au_id from #mytemp

while @@rowcount <> 0
begin
    set rowcount 0
    select * from #mytemp where au_id = @au_id
    delete #mytemp where au_id = @au_id

    set rowcount 1
    select @au_id = au_id from #mytemp
end
set rowcount 0



/********** example 2 **********/ 

declare @au_id char( 11 )

select @au_id = min( au_id ) from authors

while @au_id is not null
begin
    select * from authors where au_id = @au_id
    select @au_id = min( au_id ) from authors where au_id > @au_id
end



/********** example 3 **********/ 

set rowcount 0
select NULL mykey, * into #mytemp from authors

set rowcount 1
update #mytemp set mykey = 1

while @@rowcount > 0
begin
    set rowcount 0
    select * from #mytemp where mykey = 1
    delete #mytemp where mykey = 1
    set rowcount 1
    update #mytemp set mykey = 1
end
set rowcount 0