将数据类型nvarchar转换为int时出错

Question

I am getting the error

Error converting datatype nvarchar to int

Code:

ALTER procedure [dbo].[sp_rcdoc]
  @regno int,
  @appname varchar(50),
  @DOI datetime,
  @COV varchar(50),
  @validtill date,
  @imgloc varchar(500),
  @ImagNo char(20),
  @Purposecode varchar(50),
  @FLAG varchar(3)
AS BEGIN
   IF NOT EXISTS(SELECT regno FROM tblRCDocuments WHERE regno = @regno)
   BEGIN
       INSERT INTO tblRCDocuments(regno, appname, DOI, COV, validtill, imgloc, ImagNo, Purposecode, FLAG) 
       VALUES(@regno, @appname, @DOI, @COV, @validtill, @imgloc, @ImagNo, @Purposecode, @FLAG)
   END

Answer 1

Looks like regno is a nvarchar data type in your table and you have passed an int via your your procedure, either use a cast and convert @regno to an nvarchar or change the regno data type to an integer in the table.

DECLARE @regnocast NVARCHAR(15)

SET @regnocast = CAST(@regno AS NVARCHAR)

Then in your SELECT, INSERT and WHERE clauses use @regnocast rather than @regno