mysql_insert_id

(PHP 4, PHP 5)

mysql_insert_idGet the ID generated in the last query

Avertizare

Această extensie este dezaprobată începând cu PHP 5.5.0 și va fi eliminată în viitor. În locul ei trebuie utilizate extensiile MySQLi sau PDO_MySQL. Vedeți de asemenea ghidul MySQL: selectarea unei API și FAQ asociat pentru mai multe informații. Alternative ale acestei funcții includ:

Descrierea

int mysql_insert_id ([ resource $link_identifier = NULL ] )

Retrieves the ID generated for an AUTO_INCREMENT column by the previous query (usually INSERT).

Parametri

link_identifier

Conexiunea MySQL. Dacă identificatorul legăturii nu este specificat, se presupune că este ultima legătură deschisă cu ajutorul mysql_connect(). Dacă nu este găsită nici o astfel de legătură, se va încerca crearea uneia prin apelul mysql_connect () fără argumente. În caz că nici o conexiune nu este găsită sau stabilită, se va genera o eroare de nivelul E_WARNING.

Valorile întoarse

The ID generated for an AUTO_INCREMENT column by the previous query on success, 0 if the previous query does not generate an AUTO_INCREMENT value, or FALSE if no MySQL connection was established.

Exemple

Example #1 mysql_insert_id() example

<?php
$link 
mysql_connect('localhost''mysql_user''mysql_password');
if (!
$link) {
    die(
'Could not connect: ' mysql_error());
}
mysql_select_db('mydb');

mysql_query("INSERT INTO mytable (product) values ('kossu')");
printf("Last inserted record has id %d\n"mysql_insert_id());
?>

Note

Precauţie

mysql_insert_id() will convert the return type of the native MySQL C API function mysql_insert_id() to a type of long (named int in PHP). If your AUTO_INCREMENT column has a column type of BIGINT (64 bits) the conversion may result in an incorrect value. Instead, use the internal MySQL SQL function LAST_INSERT_ID() in an SQL query. For more information about PHP's maximum integer values, please see the integer documentation.

Notă:

Because mysql_insert_id() acts on the last performed query, be sure to call mysql_insert_id() immediately after the query that generates the value.

Notă:

The value of the MySQL SQL function LAST_INSERT_ID() always contains the most recently generated AUTO_INCREMENT value, and is not reset between queries.

Vedeți de asemenea

add a note add a note

User Contributed Notes 38 notes

up
8
heiligkind at yahoo dot de
8 years ago
If you insert a data row by using the ON DUPLICATE KEY UPDATE clause in an INSERT-statement, the mysql_insert_id() function will return not the same results as if you directly use LAST_INSERT_ID() in MySQL.

See the following example:

<?
  
// insert a datarow, primary key is auto_increment
   // value is a unique key
  
$query = "INSERT INTO test (value) VALUES ('test')";
  
mysql_query( $query );

   echo
'LAST_INSERT_ID: ',
         
mysql_query( "SELECT LAST_INSERT_ID()" ),
         
'<br>mysql_insert_id: ',
         
mysql_insert_id();

?>

This will print:

LAST_INSERT_ID: 1
mysql_insert_id: 1

In this case the function returns the same as the MySQL-Statement.
But see the insert on an existing key:

<?
   $query
= "INSERT INTO test (value)
                  VALUES ('test')
                  ON DUPLICATE KEY UPDATE value = 'test2'"
;
  
mysql_query( $query );

   echo
'LAST_INSERT_ID: ',
         
mysql_query( "SELECT LAST_INSERT_ID()" ),
         
'<br>mysql_insert_id: ',
         
mysql_insert_id();

?>

This will print:

LAST_INSERT_ID: 2
mysql_insert_id: 1

By using the ON DUPLICATE KEY UPDATE clause, only the old datarow will be modified, if the INSERT statement causes a duplicate entry, but the LAST_INSERT_ID() function returns the next auto_increment value for the primary key, which is by the way not set as the next auto_increment value in the database.

The mysql_insert_id() function returns the primary key of the old (and changed) data row. For me this is the right operation method, because the LAST_INSERT_ID() function returns a value which is not referenced to a data row at all.

Greets from Munich.

heiligkind
up
4
foros (_AT_) anthalia.com
7 years ago
Forget about using MAX to get the last inserted id. Race conditions like other users inserting between your SELECT MAX(.. and your INSERT may render your id unusable.

The WAY to get the id is by using mysql_insert_id() or the mysql SQL function LAST_INSERT_ID().

Take care, if using mysql_insert_id() you should provide the resource returned by the mysql_connect, not the resultset returned by mysql_query.
up
4
bargainbatman at gmail dot com
5 years ago
I thought this would be relevant to all the people using mysqli and looking for the ID after INSERT command :

<?php
function insert_join($catid, $disc_id) {
// insert a new item into the database
  
$conn = db_connect();
  
// insert new item
  
$demande = "insert into categories_disc values ('', '".$catid."', '".$disc_id."')";
  
$resultat = $conn->query($demande);
   if (!
$resultat) {
     return
false;
   } else {
    return
$conn->insert_id; // function will now return the ID instead of true.
}

}
?>

Then, on the other side, let us call this function as follows :

<?php
$cat_id
= insert_join($catid, $disc_id);
if(
$cat_id !== false) {
   
        echo
"<p>Category stuff was added to the database as follows : <br>";
        echo
"<hr>ID de la category : ".$cat_id."</p><hr>";

        }
?>
up
1
thomas at tgohome dot com
6 years ago
Be careful, because this operates on the last performed query, it includes UPDATEs and SELECTs as 'queries'. For example, this is what I set up.

INSERT post into database
UPDATE child forums with insert ID (insert ID is correct)
Insert ID = 0 because of last query
Send the user to their post - but fail because the insert ID is zero.

So store it in a variable like $insert_id instead of querying it every time.
up
1
buana95 att yahoo dott com
7 years ago
It's not true that mysql_insert_id() only returns the ID generated for an AUTO_INCREMENT column by the previous INSERT query.

We can use LAST_INSERT_ID() statement that will return value for mysql_insert_id().

Example:

$sql = "UPDATE `mytable` SET `mytable_id`= LAST_INSERT_ID(`mytable_id` + 1) WHERE ...;

@mysql_query($sql);
$last_id = mysql_insert_id();

LAST_INSERT_ID() statement will affect mysql_insert_id().

Regards,
Buana
up
1
guelphdad at yahoo dot com
7 years ago
and the primary reason to use neither of those last two solutions is both could result in race conditions when there is more than a single user with access to the database. when you use MAX or ORDER BY DESC LIMIT 1 you will retrieve the maximum value from the table, at that moment. That doesn't mean another user doesn't do an insertion in the primary and secondary table BEFORE you do your insertion in the secondary table. You have thus inserted a row with a correct id into the second table. Always use last_insert_id()
up
2
sander [ad] deltaserv [d0t] nl
9 years ago
In reply to: sly at noiretblanc dot org:

Make sure that auto_increment has an capital A as the first letter, otherwise it WON'T work! So you have to spell it as Auto_increment... And then it works fine.
up
1
jameszhou2001 at yahoo dot ca
11 years ago
Just a reminder, mysql_insert_id() should be called after 'mysql_affected_rows()', but BEFORE 'mysql_query("COMMIT")'.
up
0
hoangvu4000 at gmail dot com
1 year ago
How to get ID of the last updated row in MySQL?

75
down vote
I've found an answer to this problem :)

by Pomyk

SET @update_id := 0;
UPDATE some_table SET row = 'value', id = (SELECT @update_id := id)
WHERE some_other_row = 'blah' LIMIT 1;
SELECT @update_id;
EDIT by aefxx

This technique can be further expanded to retrieve the ID of every row affected by an update statement:

SET @uids := null;
UPDATE footable
   SET foo = 'bar'
WHERE fooid > 5
   AND ( SELECT @uids := CONCAT_WS(',', fooid, @uids) );
SELECT @uids;
This will return a string with all the IDs concatenated by a colon.

(questions: 1388025  form stackoverflow)
up
0
elinor dot hurst at REMOVETHIS dot gmail dot com
6 years ago
I don't get all the fuss around this.

I read:
"The value of mysql_insert_id() is affected only by statements issued within the current client connection. It is not affected by statements issued by other clients."

See: http://dev.mysql.com/doc/refman/5.0/es/mysql-insert-id.html

I can't really see what's inaccurate about that.

"In the case of a multiple-row INSERT statement, mysql_insert_id() returns the first automatically generated AUTO_INCREMENT value; if no such value is generated, it returns the last last explicit value inserted into the AUTO_INCREMENT column."

I must be missing something here but why would you insert multiple rows and then only handle the last one with some favoured behaviour? You could just as well insert them one at a time and then handle each row separately with the latest id.

I can't see what's wrong with that.

However I can see what's wrong with simply using max(my_table.id_column) because of the concurrent access issues this would imply.
up
0
Alfred Nony Mouse
6 years ago
There's nothing inherently wrong with using auto-increment fields. There's also nothing wrong with the main competetive idea, which is for the database to supply a primitive sequence of non-repeating identifiers, typically integers. This is rather like which side of the road you drive on.

The bigger problem is when people don't understand what they are doing with database access. It's like driving a car without really knowing the rules of the road. Such people wind up making bad decisions without realizing it, and then, eventually, something breaks.

Databases are complex beasts, and worth taking the time to really understand. Learn about the implications and limitations of different approaches to solving problems. Then, you will be prepared to pick a solution based on what has to work.
up
0
venimus at gmail dot com
6 years ago
Using 'SELECT MAX(id)+1...' will not return the next auto_increment id. This function is totaly unreliable by two reasons.
1. In race conditions there is no guarantee that other user will not insert new record while your function have done its work. This will render your "generated" last_id obsolete. It is rare case but it happens.
2. Most of all, if the last record(s) in the table is deleted the max id will no longer match the auto_increment value, because auto_increment never repeats numbers, it increases whenever an insert statement is completed and does not decrease if you erase the last record!!!

e.g. If you have this table with the last record deleted:
id name
1. car
2. plane
3. truck - [erased]

auto_increment is 4
but MAX(id) is 2!!!
up
0
bonatoque at yahoo.com
7 years ago
It seems that, in case of a very first INSERT, mysql_insert_id() returns 0. My guess is that MySQL does not trigger auto increment if the table is empty. Once an entry is present, it works as expected.
up
0
louis at intoplay dot com
7 years ago
If mysql_insert_id() returns 0 or null, check your auto increment field is not being set by your sql query, also if you have multiple db connections like I did, the solution is to create a seperate db connection for this query.
up
0
Anonymous
8 years ago
Take care of setting an empty value for the AUTO_INCREMENT Field else you never get a value except zero returned from mysq_insert_id() ....

Ciao Ephraim
up
0
bholbrook at servillian dot com
9 years ago
My apologies for the error below (that was modified out of a class) - as you cannot define a constant as an array.

replace the line:

<?

define
("ID",...);

?>

with

<?

$mysql_id
= mysql_query("...");

?>

$mysql_id is now an array in which the first element $mysql_id[0] holds the last inserted id.

Apologies if anyone struggled over that one... esp. the noobs.
up
0
athies at gmail dot com
9 years ago
Just a quick note. mysql_insert_id() does work with REPLACE.
up
0
ed at is-cool dot net
9 years ago
Beware, mysql_insert_id() only returns the value of the last syntaxically correct insert statement.

If your code has a problem and the insert is not understood by the server then the value of the last working insert command is returned.

Put something else in place such as "select count( id ) from table" before and after the mysql_insert_id() call to ensure that a row was inserted.
up
0
brodseba AT brodseba DOT com
9 years ago
It's possible to do the same with M$ Server.

function odbc_insert_id()
{
  $query = "SELECT @@IDENTITY AS ID;";
  $result = odbc_exec($this->m_rConnectionID, $query);
  $row = odbc_fetch_object($result);
  return $row->ID;
}
up
0
Baak
10 years ago
I believe the "resource link" being referred to is not what is returned from mysql_query() but the $link returned from mysql_connect(). mysql_insert_id() will just use the most recent connection if there is no explicit $link being used.

So the above example in the manual page itself should behave the same with mysql_insert_id($link) at the end instead of the mysql_insert_id() they used. If you had multiple connections, the $link might come in handy.

Also in reading the mysql manual itself, there is some enlightening information on the fact that this does appear to be totally safe to use because it is on a per-connection basis.

Here's the relevant quote from the manual on LAST_INSERT_ID() which is located here: http://dev.mysql.com/doc/mysql/en/Information_functions.html

"The last ID that was generated is maintained in the server on a per-connection basis. This means the value the function returns to a given client is the most recent AUTO_INCREMENT value generated by that client. The value cannot be affected by other clients, even if they generate AUTO_INCREMENT values of their own. This behavior ensures that you can retrieve your own ID without concern for the activity of other clients, and without the need for locks or transactions."

Sounds safe to me. I couldn't imagine this would be done any other way *but* on a per-connection basis, otherwise chaos would ensue. The only way to test it would be to perform a multi-thread type test. Perhaps someone is up for it and wants to post their results somewhere? :)
up
0
Wayne Theisinger
10 years ago
In response to treylane at example dot com.

It is very very very important that you put in an "or die" or some other form of error handling.

Some scripts can fail invisibly and insert invalid data throughout your whole database because of mysql_insert_id
inserting the last successful insertid rather than reporting that the last attempt failed.

example of an or die statement.

$result = mysql_query($sql)
or die("Invalid query: " . mysql_error());
$EventID = mysql_insert_id();
up
0
treylane at example dot com
11 years ago
This might be obvious, but it tripped me up - be careful when using last_insert_id() with persistent connections - running last_insert_id() after a failed update/insert/etc will return the last insert id of the last successful update/insert made by that CONNECTION rather than 0 for the number of rows updated by the previous non-working query, and who knows what the last query run on that connection was.
up
-1
benfoldsforever
7 years ago
Just wanted to re-iterate previous comment on receiving NULL or 0 return statement from calling mysql_insert_id() after insert statement.

If you have multiple mysql connections (i.e. mysql_connect() or mysqli_connect()) on the page you will need to specify the the connection you are using when calling this function!

I.e.
mysql_insert_id($MY_CONN);
up
-1
mariano at uvcms dot com
8 years ago
When used in transactions, mysql_insert_id() MUST be called before committing. Otherwise, it will return unpredictable results.
up
-1
Soroushl at gmail dot com
8 years ago
As mentioned by frumler at the-beach dot no_spam dot net

the LAST_INSERT_ID works like a charm when inserting values into tables.

I'm not sure why anyone would need mysql_insert_id() when LAST_INSERT_ID is readily available.

example:

Say you have a table called "transaction" and a table called "accounts".  Obviously each account must be created using a transaction, so every time a record is created in the accounts table, a record must be created in the transaction table containing the same account_id(auto_increment) that was just created by mysql.

Here's a simple way to do this:

<?php
$account_query
="INSERT INTO accounts (account_id,type) VALUES (NULL,'saving')";
$transaction_query="INSERT INTO transactions(transaction_id,account_id) VALUES (NULL,LAST_INSERT_ID)";

$a_query=mysql_query($account_query);
$t_query=mysql_query($transaction_query);

?>
up
-1
Steve Bond
10 years ago
If you use this function after doing an INSERT ... SELECT to insert multiple rows at once, you get the autonumber ID of the *first* row added by the INSERT.

e.g. if there are 4 records in table 'init' that have column 'type' = 2
I want to add these 4 records to table 'game'
Table game has an autonumber column 'game_id' that is currently at 32.

If I do this query:

INSERT INTO game (type, players, rounds)
SELECT type, players, rounds FROM init
WHERE type = 2

Then mysql_insert_id() will return 33, not 36.
up
-1
dtez
10 years ago
any zerofills on your id get chopped off on this function because it returns an int.
up
-1
sly at noiretblanc dot org
10 years ago
To get the NEXT insert id use the mysql query SHOW TABLE STATUS LIKE 'tablename' and get the field auto_increment...
up
-1
Anonymous
6 years ago
Why on earth are you all arguing about the best way to get the next auto_increment value? The whole point is that it increments automatically. The name should be a give away.

Don't calculate the next id, just leave the field blank and let the database issue the id itself.
up
-2
frumler at the-beach dot no_spam dot net
13 years ago
If you want to use the ID that was generated for one table and insert it into a second table, you can use SQL statements like this:

INSERT INTO foo (auto,text)
    VALUES(NULL,'text');              # generate ID by inserting NULL
INSERT INTO foo2 (id,text)
    VALUES(LAST_INSERT_ID(),'text');  # use ID in second table

...found here:
http://www.mysql.com/doc/en/Getting_unique_ID.html

It works even without inserting the NULL value for some reason ;)
The following is great for monitoring:
    $new_id = mysql_insert_id();
    print "New id: $new_id\n";

Hope it helps you all, cheers.
up
-2
RPaseur at NationalPres dot org
5 years ago
Apparently the value returned by mysql_insert_id() may be correct for BIGINT auto_increment keys below the value of INT, but it may wrap to negative when the BIGINT auto_increment passes the largest signed value of INT.  A timebomb for very large tables...

PHP 5.2.10, MySQL 5.0.81, assume the connection and selection...

<?php
// CREATE A TABLE AND ALTER IT TO A HIGH INDEX NUMBER
$sql = "CREATE TEMPORARY TABLE noise ( id BIGINT NOT NULL AUTO_INCREMENT PRIMARY KEY ) ENGINE=MEMORY";
if (!
$res = mysql_query($sql)) die(mysql_error());

$sql = "ALTER TABLE noise AUTO_INCREMENT = 2147483646";
if (!
$res = mysql_query($sql)) die(mysql_error());

// INSERT DATA TO ADD TO THE AUTO_INCREMENT INDEX
$kount = 0;
while (
$kount < 3)
{
  
$sql = "INSERT INTO noise () VALUES ()";
   if (!
$res = mysql_query($sql)) die(mysql_error());
  
$nid = mysql_insert_id($dbcx);
  
var_dump($nid);
  
$kount++;
}

// PRODUCES THIS
// int(2147483646)
// int(2147483647)
// int(-2147483648)
?>
up
-1
Anonymous
6 years ago
If i can't get a good increment.
I use this function

<?php
function get_new_id($table){
$select = 'select max(`id`) +1as `id` from `'.$table.'`  where `id` != <some big id>';
$query = mysql_query($select);
$obj = mysql_fetch_object($query);
return
$obj->id;
}
?>
up
-1
icethenet at NOSPAM dot hotmail dot com
6 years ago
Other methods seem to have problems with missing records in auto increment sometimes you will have records 1 2 5 6 most functions would return the value of 5 for next auto increment when indeed it would be 7. This is the only way I found to make this work so I can use my customer number and the record number to provide a truly unique customer number that is also useful.

$next_increment = 0;
$qShowStatus = "SHOW TABLE STATUS LIKE 'your_table'";
$qShowStatusResult = mysql_query($qShowStatus) or die(mysql_error());
$row = mysql_fetch_assoc($qShowStatusResult);
$next_increment = $row['Auto_increment'];
echo $next_increment;

then you can do something like this
echo  $next_increment ."-". rand();

My first post: I hope this is useful to someone
up
-1
vksgeneric at hotmail dot com
14 years ago
You can't do an INSERT DELAYED and expect to get anything but zero, for it runs in a separate thread, and mysql_insert_id() is tied to the current thread.
Vlad
up
-2
Ultimater at gmail dot com
5 years ago
Here's an elegant way to INSERT using UPDATE syntax.

<?php
function insert_update($table,$fields,$id=NULL)
{
    if(
$id===NULL)
    {
       
$sql="INSERT INTO $table (id) VALUES(NULL);UPDATE $table SET $fields WHERE id = LAST_INSERT_ID()";
    }else{
       
$sql="UPDATE $table SET $fields WHERE id = $id";
    }
    return
$sql;
}
?>

Usage:

<?php
$table
="`members`";
$fields="`username` = 'Ultimater',`userlevel` = 'member'";
if(!
$profile_exists)
{
//insert a record
   
$sql=insert_update($table,$fields);
   
mysql_query($sql);
}else{
//update a record
   
$sql=insert_update($table,$fields,5);
   
mysql_query($sql);
}
?>
up
-3
Anonymous
6 years ago
"Why on earth are you all arguing about the best way to get the next auto_increment value? The whole point is that it increments automatically. The name should be a give away."

Because you need the same last id value in another table. So you need a way to identify it, in order to use it in the next query. This way its easier than using a new query to get the id like ORDER BY id DESC LIMIT 1
up
-3
john k.
8 years ago
Be careful when using "insert ignore". If the unique index already exists, the record will not be added, but it WILL give you the id of the next auto_increment value even though it didn't create it.

<?php
$sql
= "insert ignore into sometable set num=10";
mysql_query($sql) or die();
echo
mysql_affected_rows()."<br>";
echo
mysql_insert_id()."<br><br>";

// same record, database is unique on 'num'
$sql = "insert ignore into sometable set num=10";
mysql_query($sql) or die();
echo
mysql_affected_rows()."<br>";
echo
mysql_insert_id()."<br><br>";
?>

would give:
1
116372

0
116373
up
-5
relic at daimi dot au dot dk
9 years ago
A bit more on return values:
mysql_insert_id() returns 0 if you haven't actually manipulated anything yet.

Also, it returns 0 even if the DB connection is lost[0] between inserting and calling mysql_insert_id() - so you can always count on getting an integer.

[0] By 'lost' I mean e.g. a DB crash. Actually closing the open link and then trying to communicate with the DB will of course result in an error.
To Top