mysql_insert_id
(PHP 4, PHP 5)
mysql_insert_id — 直近のクエリで生成された ID を得る
警告
この拡張モジュールは PHP 5.5.0 で非推奨になり、PHP 7.0.0 で削除されました。 MySQLi あるいは PDO_MySQL を使うべきです。詳細な情報は MySQL: API の選択 を参照ください。 この関数の代替として、これらが使えます。
説明
直近のクエリ (通常は INSERT) により AUTO_INCREMENT カラム用に生成された ID を取得します。
パラメータ
link_identifierMySQL 接続。指定されない場合、mysql_connect() により直近にオープンされたリンクが指定されたと仮定されます。そのようなリンクがない場合、引数を指定せずに mysql_connect() がコールした時と同様にリンクを確立します。リンクが見付からない、または、確立できない場合、
E_WARNINGレベルのエラーが生成されます。
戻り値
直近のクエリにより AUTO_INCREMENT カラム用に生成された
ID を返します。直近のクエリが AUTO_INCREMENT な値を生成しなかった
場合に 0、MySQL 接続が確立されていなかった
場合に false を返します。
例
例1 mysql_insert_id() の例
<?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("最後に挿入されたレコードの ID は、%d\n", mysql_insert_id());
?>注意
警告
mysql_insert_id() は、MySQL C API 関数
mysql_insert_id() の戻り値の型を
long 型（PHP では int と呼ばれる）
に変換します。
AUTO_INCREMENT カラムが BIGINT 型 (64 ビット) である場合、
変換結果は不正確になります。
かわりに、MySQL の SQL 関数
LAST_INSERT_ID() を SQL 内で使いましょう。
PHP の integer 型の最大値に関する詳細な説明は、
integer
のドキュメントをごらんください。
注意:
mysql_insert_id() は直近のクエリに対して働くので、 値を生成したクエリの直後に mysql_insert_id() をコールすることを忘れないようにしてください。
注意:
MySQL の SQL 関数
LAST_INSERT_ID()の値には、 常に直近の AUTO_INCREMENT の値が含まれており、クエリの間では リセットされません。
＋add a note
User Contributed Notes 11 notes
Alfred Nony Mouse ¶
16 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.
foros (_AT_) anthalia.com ¶
17 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.
elinor dot hurst at REMOVETHIS dot gmail dot com ¶
16 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.
bargainbatman at gmail dot com ¶
15 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>";
}
?>
Anonymous ¶
19 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
hoangvu4000 at gmail dot com ¶
11 years 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)
heiligkind at yahoo dot de ¶
19 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
louis at intoplay dot com ¶
17 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.
vksgeneric at hotmail dot com ¶
25 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
dhiraj dot webdeveloper at gmail dot com ¶
7 years ago
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);
?>