In MySQL how to select the top 2 rows for each group?

MySQLMySQLi Database

To select the top 2 rows from each group, use the where condition with subquery. Let us create a table. The query to create a table is as follows:

mysql> create table selectTop2FromEachGroup
   -> (
   -> Name varchar(20),
   -> TotalScores int
   -> );
Query OK, 0 rows affected (0.80 sec)

Now insert some records in the table using insert command. The query is as follows:

mysql> insert into selectTop2FromEachGroup values('John',32);
Query OK, 1 row affected (0.38 sec)
mysql> insert into selectTop2FromEachGroup values('John',33);
Query OK, 1 row affected (0.21 sec)
mysql> insert into selectTop2FromEachGroup values('John',34);
Query OK, 1 row affected (0.17 sec)
mysql> insert into selectTop2FromEachGroup values('Carol',35);
Query OK, 1 row affected (0.17 sec)
mysql> insert into selectTop2FromEachGroup values('Carol',36);
Query OK, 1 row affected (0.14 sec)
mysql> insert into selectTop2FromEachGroup values('Carol',37);
Query OK, 1 row affected (0.15 sec)

Display all records from the table using select statement. The query is as follows:

mysql> select *from selectTop2FromEachGroup;

The following is the output:

+-------+-------------+
| Name  | TotalScores |
+-------+-------------+
| John  |          32 |
| John  |          33 |
| John  |          34 |
| Carol |          35 |
| Carol |          36 |
| Carol |          37 |
+-------+-------------+
6 rows in set (0.00 sec)

Here is the query to select top 2 rows from each group using where condition and subquery:

mysql> select *from selectTop2FromEachGroup tbl
   -> where
   -> (
   ->    SELECT COUNT(*)
   ->    FROM selectTop2FromEachGroup tbl1
   ->    WHERE tbl1.Name = tbl.Name AND
   ->    tbl1.TotalScores >= tbl.TotalScores
   -> ) <= 2 ;

The following is the output:

+-------+-------------+
| Name  | TotalScores |
+-------+-------------+
| John  |          33 |
| John  |          34 |
| Carol |          36 |
| Carol |          37 |
+-------+-------------+
4 rows in set (0.06 sec)
raja
Published on 26-Feb-2019 11:41:41
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