图像数据类型无法选择为 DISTINCT，因为它不可比较

Question

我想选择 DISTINCT StudentID 或记录，但查询显示以下错误

图像数据类型不能选择为 DISTINCT，因为它不是 可比的

数据库关系

这是我的代码：

ALTER PROCEDURE [dbo].[uspSELECTALL]


AS
BEGIN

    SET NOCOUNT ON;

    SELECT  DISTINCT(SI.StudentID),SI.Surname,SI.FirstName,SI.MiddleName, SI.StudAddress , 
            SI.BirthDay,SI.Gender, SI.Nationality, SI.BirthPlace,
            SI.TelNum,SI.SchoolWhereGraduated , 
            SI.DatesWhenGraduated, SI.SchoolLastAttended,
            SI.Note,SI.StudImage,
            PI.Father_FirstName,PI.Father_LastName,
            PI.Father_MI,PI.Father_Occupation, 
            PI.Father_TelNUm, PI.Mother_FirstName, PI.Mother_LastName,
            PI.Mother_MI,PI.Mother_Occupation,PI.Mother_TelNum,
            PI.Contact_FirstName,PI.Contact_LastName,PI.Contact_MI,
            PI.Contact_Mobile,PI.Contact_TelNum,PI.Contact_Address,
            SH.SchoolYear,SH.Levels,SH.Section,SH.DateEnrolled

            FROM StudentInformation SI 
            JOIN StudentHistory SH  
                ON SI.StudentID = SH.StudentID
            JOIN ParentInformation PI
                ON PI.ParentID = SI.ParentID


END

Answer 1

将您的图像转换为varbinary。然后就可以申请DISTINCT了。