Count rows having three or more rows with a certain value in a MySQL table

Let us first create a table −

mysql> create table DemoTable
   -> (
   -> UserId int
   -> );
Query OK, 0 rows affected (0.48 sec)

Insert some records in the table using insert command −

mysql> insert into DemoTable values(10);
Query OK, 1 row affected (0.15 sec)

mysql> insert into DemoTable values(20);
Query OK, 1 row affected (0.12 sec)

mysql> insert into DemoTable values(30);
Query OK, 1 row affected (0.15 sec)

mysql> insert into DemoTable values(10);
Query OK, 1 row affected (0.14 sec)

mysql> insert into DemoTable values(10);
Query OK, 1 row affected (0.09 sec)

mysql> insert into DemoTable values(20);
Query OK, 1 row affected (0.17 sec)

mysql> insert into DemoTable values(30);
Query OK, 1 row affected (0.15 sec)

mysql> insert into DemoTable values(10);
Query OK, 1 row affected (0.19 sec)

mysql> insert into DemoTable values(20);
Query OK, 1 row affected (0.17 sec)

mysql> insert into DemoTable values(20);
Query OK, 1 row affected (0.11 sec)

mysql> insert into DemoTable values(40);
Query OK, 1 row affected (0.21 sec)

Display all records from the table using select statement −

mysql> select *from DemoTable;

Output

+----------+
| UserId   |
+----------+
|      10  |
|      20  |
|      30  |
|      10  |
|      10  |
|      20  |
|      30  |
|      10  |
|      20  |
|      20  |
|      40  |
+----------+
11 rows in set (0.00 sec)

Following is the query to count the rows having 3 or more rows with a certain value in a MySQL table −

mysql> select count(*)
   -> from (select UserId, count(*) as total
   -> from DemoTable group by UserId
   -> )tbl
   -> where total >=3;

This will produce the following output i.e. the values 10 and 20 appears three or more times. Therefore, count is for 2 values −

Output

+----------+
| count(*) |
+----------+
|        2 |
+----------+
1 row in set (0.01 sec)