PHP & mySQL obtaining last insert ID - php

Question

I'm quite new to this php/mysql deal and I'm having a hard time figuring out this situation particularily.
I have two tables, one of them is "dog" table and the other one is the "date" table. In order to insert a record in the "dog" table I MUST first insert a date in the "table" date and get the autoincrement id from that date.
Problem is that I've tried reading several posts on how to get the last insert id from a table you just inserted a record on and I can't seem to make it work.
$sql1="INSERT INTO FECHAS (fecha) VALUES (NOW())";
mysql_query($sql1);
echo $sql1;
$sql3="SELECT LAST_INSERT_ID()";
mysql_query($sql3);
echo $sql3;
$sql2="INSERT INTO PERRO (nombre_perro,FECHAS_id_fecha) VALUES ('$nombre_perro_var', '$last_id')";
echo $sql2;
if (!$mysqli->query($sql2)) {
echo 'Error: ', $mysqli->error;
}
$result2 = mysql_query($sql2);
Please forgive this code, I'm new and learning.
Thanks!

Answer 1

Use mysqli instead of mysql_
Connecting with mysqli:
$connection = mysqli_connect($hostname, $username, $password, $database_name);
Inserting into a table:
mysqli_query($connection, $sql);
Retrieving last inserted id:
$id = mysqli_insert_id($connection);

Answer 2

**Database**
CREATE TABLE MyGuests (
id INT(6) UNSIGNED AUTO_INCREMENT PRIMARY KEY,
firstname VARCHAR(30) NOT NULL,
lastname VARCHAR(30) NOT NULL,
email VARCHAR(50),
reg_date TIMESTAMP
)
**Example (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();
?>
**Example (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);
?>
**Example (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 3

A procedural solution (although it might be slightly wrong - I'm terrible at PHP)...
<?php
include('path/to/connection/stateme.nts');
$query = "
INSERT INTO fecha (fecha) VALUES (NOW());
";
mysqli_query($db,$query);
$query = "
INSERT INTO perro (nombre_perro,id_fecha) VALUES (?,?);
";
$nombre_perro = 'rover';
$id_fecha = mysqli_insert_id($db);
$stmt = mysqli_prepare($db,$query);
mysqli_stmt_bind_param($stmt, 'si', $nombre_perro,$id_fecha);
mysqli_stmt_execute($stmt);
?>
You might consider binding both queries into a transaction, so that in the event that the second query fails for some reason, then the first query fails too.