I have some weird behavior happening with a parameter passed by reference to a SQL Server Stored Procedure.

I have a variable ($FormType2) in a parameter array passed to the Stored Procedure. When the Stored Procedure is executed and I output the variable, it contains 8000 characters from a different PHP file.
The PHP file in question is included at the top of the majority of my PHP files, because it contains my frequently used functions. I don’t understand how its contents could be assigned to a variable after my SQL Query.

The Stored Procedure assigns the value of @FormType and inserts a set of XML data into a temporary table, then outputs the temp table.

Expected output:

Pre-Execute:<br>-_-_-_-<br>

Post-Execute:<br>Termination<br>

{"PAFIndex":504,"TerminationType":"Involuntary","TerminationName":"205,207,210,403","PolicyName":"TEST","OtherText":"TEST"}"

Actual Results:

Pre-Execute:<br>-_-_-_-<br>

Post-Execute:<br>-_-_-_-H:i:s', time());
//*// 8000 characters from Functions.php starting from Position 25 in the file //*//<br>

{"PAFIndex":504,"TerminationType":"Involuntary","TerminationName":"205,207,210,403","PolicyName":"TEST","OtherText":"TEST"}"

Here is the PHP code for my parameters.

        $xmlNewVals = new SimpleXMLElement("<?xml version='1.0'?><data></data>");
        array_to_xml($NewVals, $xmlNewVals);
        
        echo "nXML Data:<br>{$xmlNewVals->asXML()}<br>n"; //Confirm XML data accuracy

        unset($FormType2);
        
        $FormType2 = "-_-_-_-"; //Initialize the value.

        $stmtParams[] = array($PAFIndex, SQLSRV_PARAM_IN);
        $stmtParams[] = array($TimeStamp, SQLSRV_PARAM_IN);
        $stmtParams[] = array($xmlNewVals->asXML(), SQLSRV_PARAM_IN, SQLSRV_PHPTYPE_STREAM(SQLSRV_ENC_CHAR), SQLSRV_SQLTYPE_XML);
        $stmtParams[] = array($_SESSION['UserName'], SQLSRV_PARAM_IN);
        $stmtParams[] = array($NewValReason, SQLSRV_PARAM_IN);

        $stmtParams[] = array(&$FormType2, SQLSRV_PARAM_INOUT); //Variable passed by reference.

        $stmt = "{call HR.PAFAlterChecks(?".str_repeat(",?", count($stmtParams)-1).")}";
        
        echo "nPre-Execute:<br>{$FormType2}<br>n"; //Correctly contains the initialized value.
        
        $result = ExecSQL($stmt, $hasrows, $stmtParams);
        
        echo "nPost-Execute:<br>{$FormType2}<br>n"; //Contains 8000 characters of my Function.php file.

My ExecSQL function contains the following.

function ExecSQL($SQL, &$hasRows = false, $Parameters = array(), $BypassError = false)
{
    global $presql, $postsql, $SQLconnection, $GenericErrorMessage;
    
    unset($Result, $Error);
    $Error = "";
    
    if(empty($Parameters)){ $SQL = $presql.$SQL.$postsql; }

    $Result = sqlsrv_query($SQLconnection, $SQL, $Parameters);

    if(empty($Result)){
        $Errors = sqlsrv_errors();
        foreach($Errors as $i => $err)
        {
            $Error .= $i.": ".$err['message']."  ";
        }
        $Error .= " ({ ".$SQL." }) ";
        
        echo "<br><br>n";
        print_r($Parameters); //testing only, commented in production
        echo "<br><br>n";
    }
    else
    {
        do { $hasRows = sqlsrv_has_rows($Result); }
        while($hasRows === false && sqlsrv_next_result($Result));
    }
    
    if(!empty($Error) && empty($BypassError)){
        $bug = debug_backtrace(); 
        $res = Error(substr($bug[0]['file'], strrpos($bug[0]['file'], '\')+1), $Error, $bug[0]['line']);
        die($GenericErrorMessage."rnt".$Error); 
    }
    
    return $Result;
}

This is my Stored Procedure.

USE [FormsDataTest]
GO

/****** Object:  StoredProcedure [HR].[PAFAlterChecks]    Script Date: 05/09/2024 1:09:58 PM ******/
SET ANSI_NULLS ON
GO

SET QUOTED_IDENTIFIER ON
GO

ALTER PROCEDURE  [HR].[PAFAlterChecks]
    -- Add the parameters for the stored procedure here
    @PAFIndex INT,
    @TimeStamp DATETIME = '',
    @NewVal XML,
    @Verifier NVARCHAR(50) = '',
    @NewValReason NVARCHAR(MAX) = '',

    @FormType NVARCHAR(15) OUT

AS
BEGIN
    SET NOCOUNT ON;
    BEGIN TRY
        BEGIN TRANSACTION

        SET @FormType = (SELECT [FormType] FROM HR.PersonnelAction WHERE [index] = @PAFIndex);

        DECLARE @xmlHandle INT

        EXEC sys.sp_xml_preparedocument @xmlHandle OUTPUT, @NewVal
        
        SELECT @PAFIndex AS [PAFIndex], * INTO #NewValues
        FROM OPENXML(@xmlHandle, '/data', 2) 
        WITH ([TerminationType] NVARCHAR(50), 
              [TerminationName] NVARCHAR(MAX), 
              [PolicyName] NVARCHAR(MAX),
              [OtherText] NVARCHAR(MAX)
        )

        EXEC sys.sp_xml_removedocument @xmlHandle

        SELECT * FROM #NewValues --just making sure the xml was input correctly

        DROP TABLE #NewValues

        COMMIT TRANSACTION
        
    END TRY

    BEGIN CATCH
        ROLLBACK TRANSACTION
    END CATCH
END
GO

If I comment out the line “SELECT * FROM #NewValues” in the stored Procedure, I get the Expected Results in the $FormType2 variable. Which confuses me even more, rather than narrow anything down…