I want get count of rows from my table where X == 7
+----+----------+-------+---+
| id | username | email | X |
+----+----------+-------+---+
| 1 | | | 7 |
| 2 | | | 7 |
| 3 | | | 7 |
| 4 | | | |
| 5 | | | |
+----+----------+-------+---+
There are 3 rows where X == 7
How can i get the number of those rows?