尝试使用Laravel 5.2从存储过程中获取列时，我得到一个Array to string转换

I've been struggling with this for a while now, so I thought I would post here and see if anyone has a solution as to why it's always throwing an Array to string conversion exception. Here is my code:

Model

public function getPackageReference(Request $request) {
    $package_reference = $request->input("package_reference");

    $result = DB::select("CALL GetPackageReference(?)", array($package_reference));

    return $package_reference .$result;
}

stored procedure:

DELIMITER //
CREATE PROCEDURE GetPackageReference (IN package_reference_param VARCHAR(20))
BEGIN
    SELECT LPAD(CAST((COUNT(DISTINCT package_reference) + 1) AS CHAR(3)), 3, '0') AS package_reference
    FROM package  WHERE package_reference LIKE CONCAT(package_reference_param, '%');
END //
DELIMITER ;

Stored procedure result:

CALL GetPackageReference('T2AGB')

So in my model I would like it to return the package_reference value.

Cheers,

Tim

I managed to get the answer I was looking for by changing the model method from:

public function getPackageReference(Request $request) {
    $package_reference = $request->input("package_reference");

    $result = DB::select("CALL GetPackageReference(?)", array($package_reference));

    return $package_reference .$result;
}

to:

public function getPackageReference(Request $request) {
    $package_reference = $request->input("package_reference");

    $result = DB::select("CALL GetPackageReference(?)", array($package_reference));

    return $package_reference .$result[0]->package_reference;
}

The $result variable is an array and by typing $package_reference .$result you want to convert it to string and that's what is causing the exception. In PHP, arrays cannot be converted to strings.