I need to insert two tables into my database, one of the tables has a primary key and the other one will use that value as a foreign key.
My question is: How can I return the value of this primary key at the time of insertion? Or how can I do the PK search, without the risk of getting the value of another tuple that was inserted at the same time or soon after?
Thank you
If it's MySQLi you can use the function insert_id() .
Sample documentation :
<?php
$mysqli = new mysqli("localhost", "my_user", "my_password", "world");
/* check connection */
if (mysqli_connect_errno()) {
printf("Connect failed: %s\n", mysqli_connect_error());
exit();
}
$mysqli->query("CREATE TABLE myCity LIKE City");
$query = "INSERT INTO myCity VALUES (NULL, 'Stuttgart', 'DEU', 'Stuttgart', 617000)";
$mysqli->query($query);
printf ("New Record has id %d.\n", $mysqli->insert_id);
/* drop table */
$mysqli->query("DROP TABLE myCity");
/* close connection */
$mysqli->close();
?>
Another way when dealing with mysqli, if you do not use a class (object oriented), the function insert_id (); can be used as follows:
mysqli_insert_id($conexao_com_mysql)
instead of:
$mysqli->insert_id
This function returns the last primary key entered in that session, without the chance of you getting another primary key other than the one you just entered.