The Formal Parameter #QueryComplete was not declared as output. What might be the problem. The entire stored procedure is attached. Thanks - sql

Question

I have built the following stored procedure. It seems to be working fine and the data is going into the table. However, the Programmable Logic Controller is not able to pick the #QueryComplete value to be 1. What might be the issue here. The only error warning is as follows:
The Formal Parameter #QueryComplete was not declared as output.
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
ALTER PROCEDURE [dbo].[SP_Genealogy_WIP]
-- Add the parameters for the stored procedure here
#engine_number as nvarchar(50),
#line_id as int,
#stage_id as int,
#activity_id as int,
#activity_value as nvarchar(50),
#quantity as int,
#status as int,
#plc_YYYY as int,
#plc_MM as int,
#plc_DD as int,
#plc_HR as int,
#plc_MIN as int,
#plc_SEC as int,
-- [Sending Output]
#QueryComplete int OUTPUT
AS
BEGIN
-- SET NOCOUNT ON added to prevent extra result sets from;
-- interfering with SELECT statements.
--SET NOCOUNT ON;
Declare #plc_timestamp nvarchar(20);
SET #plc_timestamp = cast(#plc_YYYY as nvarchar(4)) + '-' + Cast(#plc_MM as nvarchar(2)) + '-' + Cast(#plc_DD as nvarchar(2)) + ' ' + Cast(#plc_HR as nvarchar(2)) + ':' + Cast(#plc_MIN as nvarchar(2)) + ':' + Cast(#plc_SEC as nvarchar(2));
SELECT #plc_timestamp as 'PLC TIMESTAMP';
-- Building the Create Statement
BEGIN TRY
INSERT INTO [dbo].[Genealogy_WIP] (
[engine_number]
,[line_id]
,[stage_id]
,[activity_id]
,[activity_value]
,[quantity]
,[status]
,[plc_timestamp]
) VALUES (
#engine_number,
#line_id,
#stage_id,
#activity_id,
#activity_value,
#quantity,
#status,
CAST(#plc_timestamp as datetime)
);
SET #QueryComplete = 1;
SELECT #QueryComplete OUTPUT;
SELECT ' Inserted successfully.' AS Response;
END TRY
BEGIN CATCH
-- statement to handle errors
IF ERROR_NUMBER()=2627
SELECT '[Error]-You cannot insert this value into the table as there is a primary key violation (in the Line ID field) or one of the inputs is incorrect.' AS Response
END CATCH
END

Answer 1

When you have to OUTPUT a value from a parameter you must
specify the parameter with the keyword OUTPUT in the parameter list (you have done it)
set a value to any OUTPUT parameter with SET or SELECT and nothing else (your line "SELECT #QueryComplete OUTPUT;" is wrong. Just write SELECT #QueryComplete = ???" where ??? is a value;
To execute a procedure with a parameter in OUTPUT you must :
Declare a variabale that will accept the returned value
Write the exec command and specify OUTPUT for the returned value
Read the returned value
Example :
DDL :
CREATE PROC P #DT DATETIME2 OUTPUT
AS
SET #DT = SYSUTCDATETIME();
GO
EXEC :
DECLARE #DATETIME2_READ DATETIME2;
EXEC P #DATETIME2_READ OUTPUT;
SELECT #DATETIME2_READ;