mysql_insert_id

(PHP 4, PHP 5)

mysql_insert_id — 取得上一步 INSERT 操作产生的 ID

说明

int mysql_insert_id ([ resource $link_identifier ] )

mysql_insert_id() 返回给定的 link_identifier 中上一步 INSERT 查询中产生的 AUTO_INCREMENT 的 ID 号。如果没有指定 link_identifier，则使用上一个打开的连接。

如果上一查询没有产生 AUTO_INCREMENT 的值，则 mysql_insert_id() 返回 0。如果需要保存该值以后使用，要确保在产生了值的查询之后立即调用 mysql_insert_id()。

Note:
MySQL 中的 SQL 函数 LAST_INSERT_ID() 总是保存着最新产生的 AUTO_INCREMENT 值，并且不会在查询语句之间被重置。

Warning

mysql_insert_id() 将 MySQL 内部的 C API 函数 mysql_insert_id() 的返回值转换成 long（PHP 中命名为 int）。如果 AUTO_INCREMENT 的列的类型是 BIGINT，则 mysql_insert_id() 返回的值将不正确。可以在 SQL 查询中用 MySQL 内部的 SQL 函数 LAST_INSERT_ID() 来替代。

Example #1 mysql_insert_id() 例子


<?php
    mysql_connect("localhost", "mysql_user", "mysql_password") or
        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());
?>

参见 mysql_query()。

User Contributed Notes

dhiraj dot webdeveloper at gmail dot com 28-Sep-2017 09:22


MySQLi Procedural

//---------------------------------------------

$last_id = mysqli_insert_id($conn);



//---------------------------------------------

 <?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);

?>

stefaniosouza at gmail dot com 25-Nov-2015 08:06


You can create a extra collum like with name "key" and generate this "key" using date() function:



$key = date("Y-m-d H:i:s:u");



Then do the INSERT



"INSERT into 'table' ('col_1', 'col_2', 'key') values ('value 1', 'value 2', '$key')";



And now, you can SELECT the last ID



"SELECT ID from 'table' where key = '$key'";

mrtbsr at hotmail dot com 05-May-2015 10:41


Get current AUTO_INCREMENT value for any table



example:



$table=$db->prepare("SHOW TABLE STATUS FROM -DatabaseName-");

$table->execute();

$sonuc = $table->get_result();

while ($satir=$sonuc->fetch_assoc()){

      if (isset($satir["Name"])== "-TableName-"){

          $ai[$satir["Name"]]=$satir["Auto_increment"];

    }

}        

echo $ai["-TableName-"];

hoangvu4000 at gmail dot com 13-Jul-2013 02:09


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)

bargainbatman at gmail dot com 25-Sep-2009 03:16


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>";



        }

?>

RPaseur at NationalPres dot org 18-Sep-2009 08:48


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)


?>

Ultimater at gmail dot com 18-May-2009 02:53


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);

}

?>

Anonymous 22-Jul-2008 11:25


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;

}

?>

thomas at tgohome dot com 06-Jul-2008 10:47


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.

icethenet at NOSPAM dot hotmail dot com 19-Jun-2008 10:13


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

Anonymous 02-May-2008 12:22


"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

elinor dot hurst at REMOVETHIS dot gmail dot com 08-Apr-2008 04:27


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.

Alfred Nony Mouse 24-Feb-2008 02:33


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.

Anonymous 20-Feb-2008 05:45


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.

venimus at gmail dot com 14-Feb-2008 04:11


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!!!

benfoldsforever 12-Oct-2007 05:04


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);

bonatoque at yahoo.com 20-Sep-2007 10:13


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.

louis at intoplay dot com 13-Aug-2007 04:53


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.

foros (_AT_) anthalia.com 31-Jul-2007 11:06


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.

guelphdad at yahoo dot com 18-Jul-2007 05:35


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()

buana95 att yahoo dott com 29-Oct-2006 10:57


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

mariano at uvcms dot com 19-Sep-2006 06:01


When used in transactions, mysql_insert_id() MUST be called before committing. Otherwise, it will return unpredictable results.

john k. 31-Jan-2006 11:55


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

heiligkind at yahoo dot de 14-Dec-2005 10:31


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

Soroushl at gmail dot com 07-Dec-2005 06:53


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);



?>

02-Dec-2005 07:48


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

bholbrook at servillian dot com 01-Sep-2005 10:50


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.

athies at gmail dot com 21-Jul-2005 11:36


Just a quick note. mysql_insert_id() does work with REPLACE.

ed at is-cool dot net 08-May-2005 07:25


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.

relic at daimi dot au dot dk 20-Feb-2005 03:57


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.

brodseba AT brodseba DOT com 15-Feb-2005 09:37


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;

}

sander [ad] deltaserv [d0t] nl 11-Nov-2004 02:38


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.

Baak 01-Oct-2004 08:04


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? :)

Steve Bond 24-Jun-2004 08:47


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.

Wayne Theisinger 26-Feb-2004 12:40


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();

dtez 12-Feb-2004 01:36


any zerofills on your id get chopped off on this function because it returns an int.

sly at noiretblanc dot org 14-Nov-2003 12:29


To get the NEXT insert id use the mysql query SHOW TABLE STATUS LIKE 'tablename' and get the field auto_increment...

treylane at example dot com 24-Apr-2003 11:36


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.

jameszhou2001 at yahoo dot ca 17-Dec-2002 03:30


Just a reminder, mysql_insert_id() should be called after 'mysql_affected_rows()', but BEFORE 'mysql_query("COMMIT")'.

frumler at the-beach dot no_spam dot net 04-Aug-2001 08:17


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.

vksgeneric at hotmail dot com 10-Dec-1999 02:14


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