SELECT_IDENTITY() not working in php - php

Question

Scenario:
I have a SQL Query INSERT INTO dbo.Grades (Name, Capacity, SpringPressure) VALUES ('{PHP}',{PHP}, {PHP})
The data types are correct.
I need to now get the latest IDENTIY which is GradeID.
I have tried the following after consulting MSDN and StackOverflow:
SELECT SCOPE_IDENTITY() which works in SQL Management Studio but does not in my php code. (Which is at the bottom), I have also tried to add GO in between the two 'parts' - if I can call them that - but still to no avail.
The next thing I tried, SELECT ##IDENTITY Still to no avail.
Lastly, I tried PDO::lastInsertId() which did not seem to work.
What I need it for is mapping a temporary ID I assign to the object to a new permanent ID I get back from the database to refer to when I insert an object that is depended on that newly inserted object.
Expected Results:
Just to return the newly inserted row's IDENTITY.
Current Results:
It returns it but is NULL.
[Object]
0: Object
ID: null
This piece pasted above is the result from print json_encode($newID); as shown below.
Notes,
This piece of code is running in a file called save_grades.php which is called from a ajax call. The call is working, it is just not working as expected.
As always, I am always willing to learn, please feel free to give advice and or criticize my thinking. Thanks
Code:
for ($i=0; $i < sizeof($grades); $i++) {
$grade = $grades[$i];
$oldID = $grade->GradeID;
$query = "INSERT INTO dbo.Grades (Name, Capacity, SpringPressure) VALUES ('" . $grade->Name . "',". $grade->Capacity .", ".$grade->SpringPressure .")";
try {
$sqlObject->executeNonQuery($query);
$query = "SELECT SCOPE_IDENTITY() AS ID";
$newID = $sqlObject->executeQuery($query);
print json_encode($newID);
} catch(Exception $e) {
print json_encode($e);
}
$gradesDictionary[] = $oldID => $newID;
}
EDIT #1
Here is the code for my custom wrapper. (Working with getting the lastInsertId())
class MSSQLConnection
{
private $connection;
private $statement;
public function __construct(){
$connection = null;
$statement =null;
}
public function createConnection() {
$serverName = "localhost\MSSQL2014";
$database = "{Fill In}";
$userName = "{Fill In}";
$passWord = "{Fill In}";
try {
$this->connection = new PDO( "sqlsrv:server=$serverName;Database=$database", $userName, $passWord);
$this->connection->setAttribute( PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION );
}
catch( PDOException $e ) {
die("Connection Failed, please contact system administrator.");
}
if ($this->connection == null) {
die("Connection Failed, please contact system administrator.");
}
}
public function executeQuery($queryString) {
$results = array();
$this->statement = $this->connection->query( $queryString );
while ( $row = $this->statement->fetch( PDO::FETCH_ASSOC ) ){
array_push($results, $row);
}
return $results;
}
public function executeNonQuery($queryString) {
$numRows = $this->connection->exec($queryString);
}
public function getLastInsertedID() {
return $this->connection->lastInsertId();
}
public function closeConnection() {
$this->connection = null;
$this->statement = null;
}
}

Answer 1

This is PDO right ? better drop these custom function wrapper...
$json = array();
for ($i=0; $i < sizeof($grades); $i++) {
//Query DB
$grade = $grades[$i];
$query = "INSERT INTO dbo.Grades (Name, Capacity, SpringPressure)
VALUES (?, ?, ?)";
$stmt = $conn->prepare($query);
$success = $stmt->execute(array($grade->Name,
$grade->Capacity,
$grade->SpringPressure));
//Get Ids
$newId = $conn->lastInsertId();
$oldId = $grade->GradeID;
//build JSON
if($success){
$json[] = array('success'=> True,
'oldId'=>$oldId, 'newId'=>$newId);
}else{
$json[] = array('success'=> False,
'oldId'=>$oldId);
}
}
print json_encode($json);

Answer 2

Try the query in this form
"Select max(GradeID) from dbo.Grades"