Yes, you can perform this in MySQL by first getting the middle value. Let us first create a table:
mysql> create table DemoTable ( UserId int NOT NULL AUTO_INCREMENT PRIMARY KEY ); Query OK, 0 rows affected (0.65 sec)
Following is the query to insert some records in the table using insert command:
mysql> insert into DemoTable values(); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable values(); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable values(); Query OK, 1 row affected (0.08 sec) mysql> insert into DemoTable values(); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable values(); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable values(); Query OK, 1 row affected (0.15 sec) mysql> insert into DemoTable values(); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable values(); Query OK, 1 row affected (0.07 sec) mysql> insert into DemoTable values(); Query OK, 1 row affected (0.06 sec) mysql> insert into DemoTable values(); Query OK, 1 row affected (0.10 sec)
Following is the query to display records from the table using select command:
mysql> select *from DemoTable;
This will produce the following output
+--------+ | UserId | +--------+ | 1 | | 2 | | 3 | | 4 | | 5 | | 6 | | 7 | | 8 | | 9 | | 10 | +--------+ 10 rows in set (0.00 sec)
Here is the query to get the middle value first:
mysql> set @middleValue=(select max(UserId) from DemoTable)/2; Query OK, 0 rows affected (0.01 sec)
Now, let us get the ascending and descending order value alternatively:
mysql> select *from DemoTable ORDER BY (IF(UserId <@middleValue,@middleValue*2- UserId,UserId-1)) DESC,UserId ASC;
This will produce the following output
+--------+ | UserId | +--------+ | 1 | | 10| | 2 | | 9 | | 3 | | 8 | | 4 | | 7 | | 6 | | 5 | +--------+ 10 rows in set (0.00 sec)