Sql 从不工作的存储过程返回字符串值

我已经创建了一个存储过程，它应该返回一个字符串值，根据该字符串值执行操作。这些查询都可以正常工作，除了@return_值（“将varchar值转换为int”）出现错误。我尝试在查询中强制转换这两个值，但都不起作用

我收到的错误是：

    Conversion failed when converting the varchar value 'Request ID: 454 captured on 2017-04-25 10:16:07' to data type int.

这是我所做工作的sql代码：

    USE [VehicleManagement]

    GO
    /****** Object:  StoredProcedure [dbo].[spSaveContractsCaptured]    
    Script Date: 2017/04/23 8:56:10 AM ******/
    SET ANSI_NULLS ON
    GO
    SET QUOTED_IDENTIFIER ON
    GO
    ALTER PROCEDURE [dbo].[sp_SaveContractsCaptured]
    @VehicleServiceRequestID int,
    @InvoiceNo nvarchar(50),
    @Amount decimal(18, 2),
    @OdometerReading float,
    @ExpiryDate datetime,
    @ServiceDate datetime,
    @CapturedBy nvarchar(50),
    @CapturedDate datetime,
    @ContractStartDate datetime,
    @PeriodExpiry nvarchar(50),
    @returnVal nvarchar(255) output

    AS
  BEGIN
  SET NOCOUNT ON

  IF NOT EXISTS (SELECT ID FROM [VehicleManagement].[dbo].[VehicleService_Captured]
  WHERE VehicleServiceRequestID = @VehicleServiceRequestID )  
  BEGIN
        INSERT INTO [VehicleService_Captured] (VehicleServiceRequestID, InvoiceNo,
        Amount, OdometerReading, ExpiryDate, ServiceDate, CapturedBy, CapturedDate, ContractStartDate, PeriodExpiry)
        VALUES (@VehicleServiceRequestID, @InvoiceNo, @Amount, @OdometerReading, @ExpiryDate, @ServiceDate, 
        @CapturedBy, @CapturedDate, @ContractStartDate, @PeriodExpiry) 

        set @returnVal = SCOPE_IDENTITY()
        RETURN CAST(@returnVal AS VARCHAR(255))
    end
else
   SET @returnVal = (SELECT 'Request ID: ' + convert(varchar,ID) +  ' captured on ' + convert(varchar,[CapturedDate],120)  FROM [VehicleManagement].[dbo].[VehicleService_Captured]
    WHERE VehicleServiceRequestID = @VehicleServiceRequestID)

   RETURN CAST(@returnVal AS nvarchar(255))
 END

---

是否有我遗漏的东西或我做错了什么？

由于Triv指向了正确的方向，您应该只设置输出变量的值并删除返回值

USE [VehicleManagement]

    GO
    /****** Object:  StoredProcedure [dbo].[spSaveContractsCaptured]    
    Script Date: 2017/04/23 8:56:10 AM ******/
    SET ANSI_NULLS ON
    GO
    SET QUOTED_IDENTIFIER ON
    GO
    ALTER PROCEDURE [dbo].[sp_SaveContractsCaptured]
    @VehicleServiceRequestID int,
    @InvoiceNo nvarchar(50),
    @Amount decimal(18, 2),
    @OdometerReading float,
    @ExpiryDate datetime,
    @ServiceDate datetime,
    @CapturedBy nvarchar(50),
    @CapturedDate datetime,
    @ContractStartDate datetime,
    @PeriodExpiry nvarchar(50),
    @returnVal nvarchar(255) output

    AS
  BEGIN
  SET NOCOUNT ON

  IF NOT EXISTS (SELECT ID FROM [VehicleManagement].[dbo].[VehicleService_Captured]
  WHERE VehicleServiceRequestID = @VehicleServiceRequestID )  
  BEGIN
        INSERT INTO [VehicleService_Captured] (VehicleServiceRequestID, InvoiceNo,
        Amount, OdometerReading, ExpiryDate, ServiceDate, CapturedBy, CapturedDate, ContractStartDate, PeriodExpiry)
        VALUES (@VehicleServiceRequestID, @InvoiceNo, @Amount, @OdometerReading, @ExpiryDate, @ServiceDate, 
        @CapturedBy, @CapturedDate, @ContractStartDate, @PeriodExpiry) 

        set @returnVal = SCOPE_IDENTITY()
    END
ELSE
   SET @returnVal = (SELECT 'Request ID: ' + convert(varchar,ID) +  ' captured on ' + convert(varchar,[CapturedDate],120)  FROM [VehicleManagement].[dbo].[VehicleService_Captured]
    WHERE VehicleServiceRequestID = @VehicleServiceRequestID)

 END

调用过程时，应声明一个变量，并将其与“out”一起使用，如：

另外，请确保您的邮件中包含255个字符就足够了。

---

希望有帮助，干杯！

返回仅用于给出错误级别。
您不应该返回结果，只设置结果就足够了。

返回类型

可选地返回int

这可以帮助你

declare @message nvarchar(255)
exec [dbo].[sp_SaveContractsCaptured] //list parameteres, @returnval = @message out