Question

下面是我的存储过程：

ALTER PROCEDURE [dbo].[IsRegionNameAllowed] (@RegionName VARCHAR(200),
                                             @RegionId   INT)
AS
  BEGIN
      --Region Name Duplicate Check
      DECLARE @IsExist BIT

      SET @IsExist=0

      IF EXISTS(SELECT *
                FROM   (SELECT DISTINCT EntityID,
                                        ResultObject.value('
                    declare default element namespace "http://schemas.datacontract.org/2004/07/LPSFS.Entity";
                    (/RegionQueueEntity/Region/RegionName)[1]', 'varchar(200)') AS RegionName
                        FROM   TransactionLPS t
                               JOIN servistreammyqueue my
                                 ON t.servistreamtransactionid = my.servistreammyqueueid
                               JOIN lkpqueuestatus lkp
                                 ON my.queuestatusid = lkp.queuestatusid
                        WHERE  SubContextID IN (SELECT ContextID
                                                FROM   lkpcontext
                                                WHERE  ContextCode = 'RGMCTX0002')
                               AND EntityID <> @RegionId) AS RegName
                WHERE  ( lower(RegName.RegionName) = lower(@RegionName)
                         AND lkp.queuestatuscode = 'QSTAPP' ))
        SET @IsExist=1
  END

但它在lkp.queuestatuscode中给出了一个错误（多部分标识符无法绑定）。请帮忙

Answer 1

lkp是子查询中的别名。外部查询的WHERE子句不再存在。如果要在外部WHERE子句中查询它，请将其包含在子选择的SELECT子句中，并观察子查询的别名是RegName而不是{{1 }}：

lkp

此外，由于所有这些都在Select * from ( select distinct EntityID, ResultObject.value(' declare default element namespace "http://schemas.datacontract.org/2004/07/LPSFS.Entity"; (/RegionQueueEntity/Region/RegionName)[1]','varchar(200)') as RegionName ,lkp.queuestatuscode from TransactionLPS t join servistreammyqueue my on t.servistreamtransactionid = my.servistreammyqueueid join lkpqueuestatus lkp on my.queuestatusid = lkp.queuestatusid where SubContextID in (Select ContextID from lkpcontext where ContextCode = 'RGMCTX0002') And EntityID <> @RegionId) as RegName Where (lower(RegName.RegionName)=lower(@RegionName) And RegName.queuestatuscode = 'QSTAPP'))测试中使用，我会删除EXISTS - 充其量，它是多余的，在最坏的情况下，它可能会导致系统产生不够优化计划。

Answer 2

试试这个 -

ALTER PROCEDURE [dbo].[IsRegionNameAllowed]
(
      @RegionName varchar(200)
    , @RegionId int
)
AS BEGIN

DECLARE @IsExist BIT
SELECT @IsExist = 0

IF EXISTS( 
    SELECT 1 
    FROM (
        SELECT DISTINCT
            EntityID,
            ResultObject.value('
                            declare default element namespace "http://schemas.datacontract.org/2004/07/LPSFS.Entity";
                            (/RegionQueueEntity/Region/RegionName)[1]', 'varchar(200)') AS RegionName
        FROM dbo.TransactionLPS t
        JOIN dbo.servistreammyqueue my ON t.servistreamtransactionid = my.servistreammyqueueid
        JOIN dbo.lkpqueuestatus lkp ON my.queuestatusid = lkp.queuestatusid
        WHERE EntityID <> @RegionId
            AND lkp.queuestatuscode = 'QSTAPP'
            AND SubContextID IN (
                            SELECT t2.ContextID 
                            FROM lkpcontext t2
                            WHERE t2.ContextCode = 'RGMCTX0002'
                        )
    ) RegName
    WHERE lower(RegName.RegionName) = lower(@RegionName) 
) SELECT @IsExist = 1

END

多部分标识符不能绑定在where子句上

2 个答案: