如何使用T-SQL从存储过程返回xml

Question

我有一个存储过程，可以调用该过程在c＃应用程序中返回数据。 我的问题是在此存储过程中有3个SELECT语句。 我需要从列中获取所有值。 从昨天的帖子中，我得出结论认为xml是行之有效的方法，这样我就可以得到我的结果。 我唯一的问题是，在我发现他只是声明@xml xml的示例中 ，我不确定这是如何工作的。 那什么也没做。 该示例使用xml作为输出参数。 那么如何使用存储过程中的xml输出参数返回值呢？ 我已经在下面发布了代码。 预先谢谢您，我将尽力回答您的所有问题。 如果您对如何实现能够读取c＃中的所有3条SELECT语句的目标还有其他建议，我欢迎您进行输入。

ALTER PROCEDURE [dbo].[L_DownTimeByLine]

@startTime datetime,
@endTime datetime,
@line int,
@xml xml output

DECLARE @QueryA nvarchar(MAX);
DECLARE @QueryB nvarchar(MAX);
DECLARE @ParamsA nvarchar(500);
DECLARE @ParamsB nvarchar(500);

SET @QueryA = N'
select min(DateAndTime) as FaultStart, max(DateAndTime) as FaultEnd, cast(max(DateAndTime) - min(DateAndTime) as time) as DownTime
from (select pt.*,
         sum(case when datediff(second, prevdt, DateAndTime) <= 1 then 0 else 1 end) over 
             (order by DateAndTime) as grp
  from (select pt.*, lag(DateAndTime) over (order by DateAndTime) as prevdt
        from IncomingProductTracker pt
        where ' + @lineAvariable + ' = 1 and
             DateAndTime > @startTime1 and
              DateAndTime < @endTime1
       ) pt
 ) pt
 group by grp
having cast(max(DateAndTime) - min(DateAndTime) as time) < @breakAllowance1
order by FaultStart';

SET @ParamsA = N'@startTime1 datetime, @endTime1 datetime, @breakAllowance1 time(0)';

SET @QueryB = N'
select min(DateAndTime) as FaultStart, max(DateAndTime) as FaultEnd,  cast(max(DateAndTime) - min(DateAndTime) as time) as DownTime
from (select pt.*,
         sum(case when datediff(second, prevdt, DateAndTime) <= 1 then 0 else 1 end) over 
             (order by DateAndTime) as grp
  from (select pt.*, lag(DateAndTime) over (order by DateAndTime) as prevdt
        from IncomingProductTracker pt
        where ' + @lineBvariable + ' = 1 and
             DateAndTime > @startTime1 and
              DateAndTime < @endTime1
       ) pt
 ) pt
 group by grp
having cast(max(DateAndTime) - min(DateAndTime) as time) < @breakAllowance1
order by FaultStart';

SET @ParamsB = N'@startTime1 datetime, @endTime1 datetime, @breakAllowance1 time(0)';

declare @tempA table (
FaultStart datetime,
FaultEnd datetime,
DownTime time(0))

declare @tempB table (
FaultStart datetime,
FaultEnd datetime,
DownTime time(0))

insert into @tempA (FaultStart, FaultEnd, DownTime)
EXEC sp_executesql @QueryA, @ParamsA, @startTime1 = @startTime, @endTime1 = @endTime, @breakAllowance1 = @breakAllowance;

insert into @tempB (FaultStart, FaultEnd, DownTime)
EXEC sp_executesql @QueryB, @ParamsB, @startTime1 = @startTime, @endTime1 = @endTime, @breakAllowance1 = @breakAllowance;

declare @tempAXml xml = (
select FaultStart, FaultEnd, DownTime 
from @tempA as A
for xml auto)

declare @tempBXml xml = (
select FaultStart, FaultEnd, DownTime 
from @tempB as B
for xml auto)

-- here you build a single XML with all the data required
set @xml = 
cast(@tempAXml as nvarchar(max)) + 
cast(@tempBXml as nvarchar(max))


select @aLineDownTime as [A Line Down Time], convert(nvarchar, @aLinePercentage) + '%' as [A Line Percentage], @bLineDownTime as [B Line Down Time], convert(nvarchar,  @bLinePercentage) + '%' as [B Line Percentage], @totalDownTime as [Total Down Time],  convert(nvarchar, @totalPercentage) + '%' as [Total Percentage]

select *
FROM @tempA

select *
FROM @tempB

Answer 1

我认为您需要删除最后几行

select @aLineDownTime as [A Line Down Time], convert(nvarchar, @aLinePercentage) + '%' as [A Line Percentage], @bLineDownTime as [B Line Down Time], convert(nvarchar,  @bLinePercentage) + '%' as [B Line Percentage], @totalDownTime as [Total Down Time],  convert(nvarchar, @totalPercentage) + '%' as [Total Percentage]

select *
FROM @tempA

select *
FROM @tempB

如果您的输出参数有效，则可能有效，否则您可能需要执行以下操作：

select @xml

结束存储过程。

然后使用ExecuteXmlReader ，这是StackOverflow上的示例