php- get last insert id

Question

I know this question has been answered many times. I tried a few of the solutions from here but nothing worked. I'm not using any PHP framework.

I have an insert operation taking place and I want to get the id of the inserted row.

Here's my code:

$qry="INSERT INTO tablename(content) VALUES('".$content."')";
setData($qry);

setData() is a user defined function which does insert operation.

//for data submit
function setData($qry)
{
    $obj=new DBCon();
    $res=$obj->submitQuery($qry);
    return $res;
}

//fetches result
function getData($qry)
{
    $obj=new DBCon();
    $res=$obj->selectQuery($qry);
    return $res;
}

This is the class I made for establishing database connectivity:

class DBCon
    {   
        private function getConnection()
        {   
                               // hostname,   username,     password,   database
            $con=mysqli_connect("localhost","root","","dbname")OR die('Could not Connect the Database');        
            return $con;
        }

        public function closeCon()
        {
            mysqli_close($con);
        }

        public function submitQuery($qry)
        {
            $result=0;
            $con=$this->getConnection();
            $result=mysqli_query($con,$qry);
            return $result;
        }

        public function selectQuery($qry)
        {
            $con=$this->getConnection();
            $res=mysqli_query($con,$qry);
            return $res;
        }
    }

To obtain the last inserted id, I wrote the following query but it did not yield any result:

SELECT LAST_INSERT_ID() FROM tablename

Is there any other method to get this?

Answer 1

LAST_INSERT_ID() only returns values that have been auto-generated by the MySQL server for an AUTO_INCREMENT column; when you insert a specific value, no auto-generation takes place and no value will be returned by LAST_INSERT_ID().

Try : $con->insert_id;