LAST_INSERT_ID

Syntax

LAST_INSERT_ID(), LAST_INSERT_ID(expr)

Description

LAST_INSERT_ID() (no arguments) returns the first automatically generated value successfully inserted for an AUTO_INCREMENT column as a result of the most recently executed INSERT statement. The value of LAST_INSERT_ID() remains unchanged if no rows are successfully inserted.

If one gives an argument to LAST_INSERT_ID(), then it will return the value of the expression and the next call to LAST_INSERT_ID() will return the same value. The value is also sent to the client and can be accessed by the mysql_insert_id function.

For example, after inserting a row that generates an AUTO_INCREMENT value, you can get the value like this:

SELECT LAST_INSERT_ID(); +------------------+ | LAST_INSERT_ID() | +------------------+ | 9 | +------------------+

You can also use LAST_INSERT_ID() to delete the last inserted row:

DELETE FROM product WHERE id = LAST_INSERT_ID();

If no rows were successfully inserted, LAST_INSERT_ID() returns 0.

You can also use INSERT...RETURNING for this purpose.

The value of LAST_INSERT_ID() will be consistent across all versions if all rows in the INSERT or UPDATE statement were successful.

The currently executing statement does not affect the value of LAST_INSERT_ID(). Suppose that you generate an AUTO_INCREMENT value with one statement, and then refer to LAST_INSERT_ID() in a multiple-row INSERT statement that inserts rows into a table with its own AUTO_INCREMENT column. The value of LAST_INSERT_ID() will remain stable in the second statement; its value for the second and later rows is not affected by the earlier row insertions. (However, if you mix references to LAST_INSERT_ID() and LAST_INSERT_ID(expr), the effect is undefined.)

If the previous statement returned an error, the value of LAST_INSERT_ID() is undefined. For transactional tables, if the statement is rolled back due to an error, the value of LAST_INSERT_ID() is left undefined. For manual ROLLBACK, the value of LAST_INSERT_ID() is not restored to that before the transaction; it remains as it was at the point of the ROLLBACK.

Within the body of a stored routine (procedure or function) or a trigger, the value of LAST_INSERT_ID() changes the same way as for statements executed outside the body of these kinds of objects. The effect of a stored routine or trigger upon the value of LAST_INSERT_ID() that is seen by following statements depends on the kind of routine:

• If a stored procedure executes statements that change the value of LAST_INSERT_ID(), the new value will be seen by statements that follow the procedure call.

• For stored functions and triggers that change the value, the value is restored when the function or trigger ends, so following statements will not see a changed value.

Examples

CREATE TABLE t (  id INTEGER UNSIGNED AUTO_INCREMENT PRIMARY KEY,   f VARCHAR(1))  ENGINE = InnoDB;  INSERT INTO t(f) VALUES('a');  SELECT LAST_INSERT_ID(); +------------------+ | LAST_INSERT_ID() | +------------------+ | 1 | +------------------+  INSERT INTO t(f) VALUES('b');  INSERT INTO t(f) VALUES('c');  SELECT LAST_INSERT_ID(); +------------------+ | LAST_INSERT_ID() | +------------------+ | 3 | +------------------+  INSERT INTO t(f) VALUES('d'),('e');  SELECT LAST_INSERT_ID(); +------------------+ | LAST_INSERT_ID() | +------------------+ | 4 | +------------------+  SELECT * FROM t; +----+------+ | id | f | +----+------+ | 1 | a | | 2 | b | | 3 | c | | 4 | d | | 5 | e | +----+------+  SELECT LAST_INSERT_ID(12); +--------------------+ | LAST_INSERT_ID(12) | +--------------------+ | 12 | +--------------------+  SELECT LAST_INSERT_ID(); +------------------+ | LAST_INSERT_ID() | +------------------+ | 12 | +------------------+  INSERT INTO t(f) VALUES('f');  SELECT LAST_INSERT_ID(); +------------------+ | LAST_INSERT_ID() | +------------------+ | 6 | +------------------+  SELECT * FROM t; +----+------+ | id | f | +----+------+ | 1 | a | | 2 | b | | 3 | c | | 4 | d | | 5 | e | | 6 | f | +----+------+  SELECT LAST_INSERT_ID(12); +--------------------+ | LAST_INSERT_ID(12) | +--------------------+ | 12 | +--------------------+  INSERT INTO t(f) VALUES('g');  SELECT * FROM t; +----+------+ | id | f | +----+------+ | 1 | a | | 2 | b | | 3 | c | | 4 | d | | 5 | e | | 6 | f | | 7 | g | +----+------+

See Also

• mysql_insert_id

• AUTO_INCREMENT

• AUTO_INCREMENT handling in InnoDB

• Sequences - an alternative to auto_increment

• INSERT...RETURNING

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