SQL存储过程WHERE CLAUSE变量

Question

我有一个存储过程，我无法弄清楚字符串是如何构建的。

当我没有变量时，SQL语句工作正常，所以它绝对是我写它的方式。我只是一个初学者，对语法不太了解。

这是代码：

CREATE PROCEDURE [dbo].[SP_SLINVOICE]
@varCURRENCY AS VARCHAR(3)

AS
BEGIN 
SET NOCOUNT ON;

DECLARE @SQL NVARCHAR(MAX);

SELECT @SQL = N'SELECT  dbo.invmaster.InvNumber

              FROM dbo.invmaster INNER JOIN dbo.invdetail ON dbo.invmaster.INVMasterID = dbo.invdetail.INVMasterID 
              INNER JOIN dbo.Company ON dbo.invmaster.InvCompanyID = dbo.Company.CompanyID

              WHERE dbo.InvMaster.InvCurrency = '' + @varCURRENCY + ''
              AND dbo.invmaster.DocType <> ''MC''
              ORDER BY dbo.invmaster.InvNumber ASC;';


EXEC sp_executesql @sql;

执行时@varCURRENCY不会给我一个错误。 但是，当我通过参数传递它时，它不起作用。

如果您能看到问题所在，请告诉我。

提前致谢

Answer 1

您的SQL最终结果如下：

WHERE   dbo.InvMaster.InvCurrency = '@varCURRENCY'

所以你不是在寻找参数的值，你正在寻找@Currency ，我不确定你为什么使用动态SQL，以下应该可以正常工作：

CREATE PROCEDURE [dbo].[SP_SLINVOICE] @varCURRENCY AS VARCHAR(3)
AS
BEGIN 
SET NOCOUNT ON;

    SELECT  dbo.invmaster.InvNumber
    FROM dbo.invmaster 
        INNER JOIN dbo.invdetail 
            ON dbo.invmaster.INVMasterID = dbo.invdetail.INVMasterID 
        INNER JOIN dbo.Company 
            ON dbo.invmaster.InvCompanyID = dbo.Company.CompanyID
    WHERE dbo.InvMaster.InvCurrency = @varCURRENCY
    AND dbo.invmaster.DocType <> 'MC'
    ORDER BY dbo.invmaster.InvNumber ASC;

END

如果由于某些其他原因需要动态SQL，可以使用以下命令将@varCURRENCY作为参数传递给sp_executesql ：

DECLARE @SQL NVARCHAR(MAX);

SELECT @SQL = N'SELECT  dbo.invmaster.InvNumber

              FROM dbo.invmaster INNER JOIN dbo.invdetail ON dbo.invmaster.INVMasterID = dbo.invdetail.INVMasterID 
              INNER JOIN dbo.Company ON dbo.invmaster.InvCompanyID = dbo.Company.CompanyID

              WHERE dbo.InvMaster.InvCurrency = @varCURRENCY 
              AND dbo.invmaster.DocType <> ''MC''
              ORDER BY dbo.invmaster.InvNumber ASC;';


EXEC sp_executesql @sql, N'@varCURRENCY VARCHAR(3)', @varCURRENCY;

Answer 2

如果要将变量传递给sp_executesql上下文，则需要将其作为参数传递。

EXECUTE sp_executesql 
          @sql,
          N'@varCurrency varchar(3)',
          @varcurrency= @varCurrency;

http://msdn.microsoft.com/en-gb/library/ms188001.aspx

虽然为什么你不只是使用

select ...  where dbo.InvMaster.InvCurrency = @varCURRENCY 

而不是executeql超出了我。

Answer 3

您需要传递@varCURRENCY作为参数，从Sp中删除额外的' 。

WHERE dbo.InvMaster.InvCurrency = ' + @varCURRENCY + '

或者不要使用动态查询

CREATE PROCEDURE [dbo].[SP_SLINVOICE]
@varCURRENCY AS VARCHAR(3)

AS
BEGIN 
SET NOCOUNT ON;

 SELECT  dbo.invmaster.InvNumber

              FROM dbo.invmaster INNER JOIN dbo.invdetail ON dbo.invmaster.INVMasterID = dbo.invdetail.INVMasterID 
              INNER JOIN dbo.Company ON dbo.invmaster.InvCompanyID = dbo.Company.CompanyID

              WHERE dbo.InvMaster.InvCurrency =  @varCURRENCY 
              AND dbo.invmaster.DocType <> 'MC'
              ORDER BY dbo.invmaster.InvNumber ASC;