To generate a row index, use ROW_NUMBER(). Let us first create a table −
mysql> create table DemoTable ( Name varchar(40) ); Query OK, 0 rows affected (0.49 sec)
Insert some records in the table using insert command −
mysql> insert into DemoTable values('Chris'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values('Chris'); Query OK, 1 row affected (0.22 sec) mysql> insert into DemoTable values('Chris'); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable values('Robert'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable values('Robert'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values('Adam'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable values('Adam'); Query OK, 1 row affected (0.22 sec) mysql> insert into DemoTable values('Adam'); Query OK, 1 row affected (0.08 sec) mysql> insert into DemoTable values('Adam'); Query OK, 1 row affected (0.08 sec)
Display all records from the table using select statement −
mysql> select *from DemoTable;
This will produce the following output −
+--------+ | Name | +--------+ | Chris | | Chris | | Chris | | Robert | | Robert | | Adam | | Adam | | Adam | | Adam | +--------+ 9 rows in set (0.00 sec)
Following is the query to generate a row index in MySQL SELECT statement. Here, we have set rank for duplicate names −
mysql> select Name, row_number() over (partition by Name) as `Rank` from DemoTable;
This will produce the following output −
+--------+------+ | Name | Rank | +--------+------+ | Adam | 1 | | Adam | 2 | | Adam | 3 | | Adam | 4 | | Chris | 1 | | Chris | 2 | | Chris | 3 | | Robert | 1 | | Robert | 2 | +--------+------+ 9 rows in set (0.00 sec)