Let us first create a table −
mysql> create table DemoTable ( Id int NOT NULL AUTO_INCREMENT PRIMARY KEY, Value char(1) ); Query OK, 0 rows affected (0.66 sec)
Insert some records in the table using insert command −
mysql> insert into DemoTable(Value) values('X'); Query OK, 1 row affected (0.20 sec) mysql> insert into DemoTable(Value) values('Y'); Query OK, 1 row affected (0.09 sec) mysql> insert into DemoTable(Value) values('X'); Query OK, 1 row affected (0.30 sec) mysql> insert into DemoTable(Value) values('X'); Query OK, 1 row affected (0.07 sec) mysql> insert into DemoTable(Value) values('Y'); Query OK, 1 row affected (0.17 sec) mysql> insert into DemoTable(Value) values('Z'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable(Value) values('Z'); Query OK, 1 row affected (0.11 sec)
Display all records from the table using select statement −
mysql> select *from DemoTable;
This will produce the following output −
+----+-------+ | Id | Value | +----+-------+ | 1 | X | | 2 | Y | | 3 | X | | 4 | X | | 5 | Y | | 6 | Z | | 7 | Z | +----+-------+ 7 rows in set (0.00 sec)
Case 1 − Following is the query to group but randomly −
mysql> select DemoTable.* from DemoTable join ( select Value, rand() as `random_Value` from DemoTable group by Value ) tbl2 on DemoTable.Value = tbl2.Value order by tbl2.`random_Value`;
This will produce the following output −
+----+-------+ | Id | Value | +----+-------+ | 6 | Z | | 7 | Z | | 1 | X | | 3 | X | | 4 | X | | 2 | Y | | 5 | Y | +----+-------+ 7 rows in set (0.00 sec)
Case 2 − Let us run the above query again to display since we are showing random records −
mysql> select DemoTable.* from DemoTable join ( select Value, rand() as `random_Value` from DemoTable group by Value ) tbl2 on DemoTable.Value = tbl2.Value order by tbl2.`random_Value`;
This will produce the following output −
+----+-------+ | Id | Value | +----+-------+ | 2 | Y | | 5 | Y | | 6 | Z | | 7 | Z | | 1 | X | | 3 | X | | 4 | X | +----+-------+ 7 rows in set (0.00 sec)