Hàm Last_Insert_Id() của MySQL dùng để biết số dãy vừa được gán bởi AUTO_INCREMENT.
Ví dụ
mysql> CREATE TABLE Employee(Id INT PRIMARY KEY NOT NULL AUTO_INCREMENT, Name VARCHAR(5));
Query OK, 0 rows affected (0.13 sec)
mysql> INSERT INTO Employee(Name) VALUES('Harvinder');
Query OK, 1 row affected (0.06 sec)
mysql> INSERT INTO Employee(Name) VALUES('Suresh');
Query OK, 1 row affected (0.07 sec)
mysql> SELECT * FROM Employee;
+----+---------+
| Id | Name |
+----+---------+
| 1 | Harvinder|
| 2 | Suresh |
+----+---------+
2 rows in set (0.00 sec)
mysql> SELECT LAST_INSERT_ID();
+------------------+
| LAST_INSERT_ID() |
+------------------+
| 2 |
+------------------+
1 row in set (0.00 sec)