为什么查询没有返回结果

Question

I am trying to write a SQL query to fulfil the below requirements. All the naming conventions are correct for the tables, columns, and values. Yet my query does not return anything.

• Check if the SpecializationCode exists in the Specialization table. If it does not exist, insert the SpecializationCode and SpecializationName into the Specialization table
• Insert doctor details into the Doctor table
• Insert the newly generated DoctorID and the given SpecializationCode into DoctorSpecialization table with SpecializationDate as current date

CREATE PROCEDURE usp_AddDoctorDetails
    (@DoctorName VARCHAR(25),
     @SpecializationCode CHAR(3),  
     @SpecializationName VARCHAR(20))
AS
BEGIN
    DECLARE @DoctorID INT
    
    SELECT @DoctorID = DoctorID 
    FROM Doctor 
    WHERE DoctorName = @DoctorName

    BEGIN TRY
        IF NOT EXISTS (SELECT SpecializationCode FROM Specialization 
                       WHERE @SpecializationCode = SpecializationCode)
        BEGIN
            INSERT INTO Specialization (SpecializationCode, SpecializationName)
            VALUES (@SpecializationCode, @SpecializationName)

            INSERT INTO Doctor (DoctorID, DoctorName)
            VALUES (@DoctorID, @DoctorName)
 
            INSERT INTO DoctorSpecialization (DoctorID, SpecializationCode, SpecializationDate)
            VALUES (@DoctorID, @SpecializationCode, GETDATE())

            RETURN -1
        END
    END TRY
    BEGIN CATCH
        RETURN -99
    END CATCH
END
GO

Answer 1

Replace Return -1 with SELECT 1 / 0 AS Error; in TRY Block Replace Return -99 with ERROR_LINE() AS ErrorLine, ERROR_MESSAGE() AS ErrorMessage; in CATCH Block

Your procedure look like this after changes with only TRY CATCH block

 BEGIN try 
      IF NOT EXISTS (SELECT specializationcode 
                     FROM   specialization 
                     WHERE  @SpecializationCode = specializationcode) 
        BEGIN 
            INSERT INTO specialization 
                        (specializationcode, 
                         specializationname) 
            VALUES     (@SpecializationCode, 
                        @SpecializationName) 

            INSERT INTO doctor 
                        (doctorid, 
                         doctorname) 
            VALUES     (@DoctorID, 
                        @DoctorName) 

            INSERT INTO doctorspecialization 
                        (doctorid, 
                         specializationcode, 
                         specializationdate) 
            VALUES     (@DoctorID, 
                        @SpecializationCode, 
                        Getdate()) 

            SELECT
             1 / 0 AS Error; 
        END 
  END try 

  BEGIN catch 
    SELECT 
        ERROR_LINE() AS ErrorLine,
        ERROR_MESSAGE() AS ErrorMessage;
  END catch