文本、文本和图像数据类型不能进行比较或排序，除非使用IS NULL或LIKE操作符

Question

我创建了一个过程(使用SQL Server 2008)从image表检索图像数据，但这个过程给我一个错误

"文本、文本和图像数据类型不能比较或排序，除非使用IS NULL或LIKE操作符。"

我的程序是这样的:

Create procedure [dbo].[xp_GetImage]
@companyId  udtId
as  
begin
/*=============================================================================
*   Constants
*============================================================================*/
declare 
        @SUCCESS            smallint,
        @FAILED             smallint,
        @ERROR_SEVERITY     smallint,
        @ERROR_STATE1       smallint,
        @theErrorMsg        nvarchar(4000),
        @theErrorState      int,
        @chartCount         int,
        @provider           varchar(128),
        @projectCount       int
select  
        @SUCCESS    =   0,  
        @FAILED     =   -1, 
        @ERROR_SEVERITY = 11,
        @ERROR_STATE1 = 1
begin try
    -- Get the Image
    select  Logo, LogoName,LogoSize
              from CompanyLogo                  
     where CompanyId = @companyId         
  order by Logo desc
end try

begin catch
    set @theErrorMsg = error_message()
    set @theErrorState = error_state()
    raiserror (@theErrorMsg, @ERROR_SEVERITY, @theErrorState)
    return (@FAILED)
end catch
end 
print 'created the procedure xp_GetImage'
go
---end of the procedure
grant EXECUTE on xp_GetImage to public
go

Answer 1

别忘了CAST()。它让我摆脱了在文本域中查找字符串的麻烦，也就是

SELECT lutUrl WHERE CAST(Url AS varchar) = 'http://www.google.com.au'

对我有帮助的简介是在Mind Chronicles。作者还讨论了排序问题。

Answer 2

按二进制图像数据排序(排序)没有意义。为什么不按其他列排序呢?

修改代码:

-- Get the Image
  SELECT Logo, LogoName,LogoSize
    FROM CompanyLogo                  
   WHERE CompanyId = @companyId         
ORDER BY Logo desc

:

-- Get the Image
  SELECT Logo, LogoName,LogoSize
    FROM CompanyLogo                  
   WHERE CompanyId = @companyId         
ORDER BY LogoName