mysql : select count when id have multiple same value

Question

+------+---------+
| id   | object  |
+------+---------+
| 1    |    1    |
| 1    |    2    |
| 1    |    3    |
| 1    |    4    |
| 2    |    3    |
| 2    |    4    |
| 3    |    5    |
| 3    |    3    |
| 3    |    4    |
+------+---------+

我想选择计数具有相同值的id，所以结果是，id 1有4个相同的值，id 2有2个相同的值，id 3有3个相同的值。

+------+
| id   | 
+------+
| 4    |  
| 2    |   
| 3    |  
+------+

谢谢大师的帮助。

Answer 1

SELECT id, COUNT(object) FROM tablename GROUP BY id