MYSQL和PHP将LAST_INSERT_ID（）保存为本地变量

Question

I am having some issues with storing data in database from a PHP form. The form calls a file called insert which I have copied below. Basically, I need to store details into the table scout and save the last_insert_id() as a local variable to be used when I insert items into the table emergencyContact. Then the emergencycontacts last_insert_id() needs to be saved and then stored in the scout table. However at the moment it is not working. I don't think I have storing/using the variable correct yet.

<?php
$con = mysql_connect("localhost","user","password");
if (!$con) {
    die('Could not connect: ' . mysql_error());
}
mysql_select_db("lex", $con);

mysql_query("INSERT INTO Scout (Unit_id, FirstName, SurName, DOB, Address, Telephone, School, Religion, Ethenic, Child_Doc, Doc_Phone, Allergies, Active)
VALUES ('$_POST[unitid]','$_POST[firstname]','$_POST[lastname]','$_POST[dob]','$_POST[address]','$_POST[phone]','$_POST[school]','$_POST[religion]','$_POST[ethnicidentity]','$_POST[doctorsname]','$_POST[doctorsnumber]','$_POST[health]','$_POST[radio]')");

mysql_query("SET @scout_id = LAST_INSERT_ID()");

mysql_query("INSERT INTO EmergencyContact (Scout_id, Name, Tel, Address) 
VALUES(@scout_id,'$_POST[emergencycontact]','$_POST[emergencyphone]',$_POST[emergencyaddress]')");

mysql_query("SET @emergency_id = LAST_INSERT_ID()");

mysql_close($con);
?>

Answer 1

use mysql_insert_id()

$idInsertLast = mysql_insert_id();

the result is the last AUTOINCREMENT id inserted from this connection/user. if you have 200 different users doing insert transactions around the same time, each will receive his/her last id, not anyone else's, even if between the time userA inserts a record and the time he/she calls mysql_insert_id(), userB and userC have inserted records of their own.

be careful not to share connections between users, as long as each user opens his/her own connection to DB, everything will be fine.

NOTE: mysql_query and the rest of the library have been deprecated and will eventually be removed from future php versions.