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javasql-serverjdbccallable-statement

JDBC SQL Server Stored Procedure with ResultSet, return value, and output parameters


I am in the process of converting an application from Jython to compiled Java. The application uses a host of SQL Server stored procedures to do CRUD operations. All of the procedures are defined with a return value that indicates status, and some output parameters used to provide feedback to the application. Most of the procedures also return a result set. I'm struggling with how to retrieve the return value and the result set and the output parameters.

I normally work with C# so the nuances of JDBC are new to me. I've been testing with one of the procedures that does an insert to the database and then does a select on the inserted object.

Here's a simplified example procedure just to use for the purpose of illustration. The actual procedures are more complex than this.

CREATE PROCEDURE [dbo].[sp_Thing_Add]
(
   @Name NVARCHAR(50),
   @Description NVARCHAR(100),
   @ResultMessage NVARCHAR(200) = N'' OUTPUT
)
AS
BEGIN
   SET NOCOUNT ON
   
   DECLARE @Result INT = -1
   DECLARE @ResultMessage = 'Procedure incomplete'
   
   BEGIN TRY
      INSERT INTO Things (Name, Description) VALUES (@Name, @Description)

      SELECT * FROM Things WHERE ThingID = SCOPE_IDENTITY()
   END TRY
   BEGIN CATCH
      SELECT @Result = CASE WHEN ERROR_NUMBER() <> 0 THEN ERROR_NUMBER() ELSE 1 END,
         @ResultMessage = ERROR_MESSAGE()
      GOTO EXIT_SUB
   END CATCH
SUCCESS:
   SET @Result = 0
   SET @ResultMessage = N'Procedure completed successfully'
   RETURN @Result
EXIT_SUB:
   IF @Result <> 0
   BEGIN
   -- Do some error handling stuff
   END
   RETURN @Result

      

I can successfully retrieve the ResultSet using the following code.

var conn = myConnectionProvider.getConnection();
String sql = "{? = call dbo.sp_Thing_Add(?, ?, ?)}"

call = conn.prepareCall(sql);
call.registerOutParameter(1, TYPES.Integer); // Return value
call.setString("Name", thing.getName());
call.setString("Description", thing.getDescription());
call.registerOutParameter("ResultMessage", TYPES.NVARCHAR);
ResultSet rs = call.executeQuery();

// Try to get the return value. This appears to close the ResultSet and prevents data retrieval.
//int returnValue = call.getInt(1);
// Normally there'd be a check here to make sure things executed properly, 
// and if necessary the output parameter(s) may also be leveraged

if (rs.next()) {
   thing.setId(rs.getLong("ThingID"));
   // Other stuff actually happens here too...
}

If I try retrieving the return value using the line that's commented out, I get an error stating that the ResultSet is closed.

com.microsoft.sqlserver.jdbc.SQLServerException: The result set is closed.

I've been through the documentation and have seen how to do return values, output parameters, and result sets. But how can I leverage all 3?


Solution

  • Given the order of processing in your stored procedure (insert, select, then populate result parameters), you need to process the result set before you retrieve the return value with CallableStatement.getXXX.