Error while using user-defined table type in sql --> Operand type clash: varchar is incompatible with "user defined table type"

Question

I'm trying to use a user-defined table in a stored procedure but while running my procedure im getting error as

 "Operand type clash: varchar is incompatible with ..." 

I have defined one user defined tabel as below:

CREATE TYPE [myUserTable] AS TABLE(
    [Id] [nvarchar](10) NOT NULL)

Stored procedure:

Create PROCEDURE FETCHUSER
(@USERS [myUserTable] readonly,
   @Firstname varchar(max))
select * from UserTable as ut, @USERS as mt where mt.Id = ut.Id

While executing, I have supplied input params as:

@USERS = 'Sample'

but getting error as

"Operand type clash: varchar is incompatible with ..." 

Please help me out. Any suggestions, appreciated!

Answer 1

You need to pass a parameter value which exists. If you want to select from myUserTable , then pass that instead of sample . Also, you need to pass a FirstName of varchar(max) type. You will need to make sure that whatever you pass is compatible with this type. Finally, if my.Id and ut.Id are of incompatible types, then you will need to convert one of them into the other's type for the sake of comparison.

Answer 2

It seems you are declaring a @USERS variable as varchar whereas the expected stored procedure parameter type is myUserTable . To pass a table-valued parameter value, you need to declare a variable of the table type, insert rows into the table variable, and then call the proc.

Below is a refactored example based on the code in your question using modern ISO SQL join syntax. Not sure how @FirstName is used in your actual code but I kept it here.

CREATE PROCEDURE FETCHUSER
    @USERS [myUserTable] readonly
   ,@Firstname varchar(max)
AS
SELECT *
FROM UserTable AS ut
JOIN @USERS AS mt ON mt.Id = ut.Id;
GO

DECLARE @myUserTable [myUserTable];
INSERT INTO @myUserTable(ID) VALUES(N'Sample');

EXEC FETCHUSER @USERS = @myUserTable, @FirstName = '';
GO

Answer 3

I think the following code can help you

CREATE TYPE [dbo].[myUserTable] AS TABLE([Id] [nvarchar](10) NOT NULL);

CREATE PROCEDURE [dbo].FETCHUSER
@USERS [myUserTable] READONLY,
@Firstname VARCHAR(MAX)
AS
BEGIN
    SELECT *
    FROM   UserTable    AS ut
           JOIN @USERS  AS mt
                ON  mt.Id = ut.Id;
END
GO


DECLARE @users [myUserTable]

INSERT INTO @users
VALUES
   (
    '1'
   ) ,
   (
    '2'
   ) 

EXEC FETCHUSER @users,
     'yourFirstName'