php- get last insert id - php

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;

Answer 2

Try This way.
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
$sql = "INSERT INTO MyGuests (firstname, lastname, email)
VALUES ('First Name', 'Last Name', 'first#example.com')";
if ($conn->query($sql) === TRUE) {
$last_id = $conn->insert_id;
echo "New record created successfully. Last inserted ID is: " . $last_id;
} else {
echo "Error: " . $sql . "<br>" . $conn->error;
}

Answer 3

MySQLi Object-oriented
<?php
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "myDB";
// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
$sql = "INSERT INTO MyGuests (firstname, lastname, email)
VALUES ('John', 'Doe', 'john#example.com')";
if ($conn->query($sql) === TRUE) {
$last_id = $conn->insert_id;
echo "New record created successfully. Last inserted ID is: " . $last_id;
} else {
echo "Error: " . $sql . "<br>" . $conn->error;
}
$conn->close();
?>
MySQLi Procedural
<?php
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "myDB";
// Create connection
$conn = mysqli_connect($servername, $username, $password, $dbname);
// Check connection
if (!$conn) {
die("Connection failed: " . mysqli_connect_error());
}
$sql = "INSERT INTO MyGuests (firstname, lastname, email)
VALUES ('John', 'Doe', 'john#example.com')";
if (mysqli_query($conn, $sql)) {
$last_id = mysqli_insert_id($conn);
echo "New record created successfully. Last inserted ID is: " . $last_id;
} else {
echo "Error: " . $sql . "<br>" . mysqli_error($conn);
}
mysqli_close($conn);
?>
PDO
<?php
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "myDBPDO";
try {
$conn = new PDO("mysql:host=$servername;dbname=$dbname", $username, $password);
// set the PDO error mode to exception
$conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$sql = "INSERT INTO MyGuests (firstname, lastname, email)
VALUES ('John', 'Doe', 'john#example.com')";
// use exec() because no results are returned
$conn->exec($sql);
$last_id = $conn->lastInsertId();
echo "New record created successfully. Last inserted ID is: " . $last_id;
}
catch(PDOException $e)
{
echo $sql . "<br>" . $e->getMessage();
}
$conn = null;
?>

Answer 4

$last_id = $conn->insert_id;