Selecting the top occurring entries in MySQL from a table with duplicate values?

Let us first create a table −

mysql> create table DemoTable610 (SubjectName varchar(100)); Query OK, 0 rows affected (0.63 sec)

Insert some records in the table using insert command −

mysql> insert into DemoTable610 values('MySQL'); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable610 values('Java'); Query OK, 1 row affected (0.23 sec) mysql> insert into DemoTable610 values('MySQL'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable610 values('MongoDB'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable610 values('MySQL'); Query OK, 1 row affected (0.23 sec) mysql> insert into DemoTable610 values('MySQL'); Query OK, 1 row affected (0.08 sec) mysql> insert into DemoTable610 values('Java'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable610 values('MongoDB'); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable610 values('C'); Query OK, 1 row affected (0.16 sec) mysql> insert into DemoTable610 values('C++'); Query OK, 1 row affected (0.13 sec) mysql> insert into DemoTable610 values('MongoDB'); Query OK, 1 row affected (0.12 sec) mysql> insert into DemoTable610 values('MySQL'); Query OK, 1 row affected (0.21 sec) mysql> insert into DemoTable610 values('Java'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable610 values('Python'); Query OK, 1 row affected (0.08 sec) mysql> insert into DemoTable610 values('MySQL'); Query OK, 1 row affected (0.15 sec)

Display all records from the table using select statement −

mysql> select *from DemoTable610;

This will produce the following output −

+-------------+ | SubjectName | +-------------+ | MySQL       | | Java       | | MySQL     | | MongoDB     | | MySQL     | | MySQL     | | Java       | | MongoDB    | | C       | | C++       | | MongoDB | | MySQL    | | Java     | | Python    | | MySQL    | +-------------+ 15 rows in set (0.00 sec)

Here is the query to select only the top occurring entries −

mysql> select SubjectName from ( select SubjectName from DemoTable610 group by SubjectName order by count(SubjectName) DESC LIMIT 2 ) AS tbl order by SubjectName;

This will produce the following output −

+-------------+ | SubjectName | +-------------+ | Java       | | MySQL       | +-------------+ 2 rows in set (0.04 sec)