MySQL 查询 DISTINCT，COUNT

Question

我正在尝试使用 SELECT DISTINCT 从这张表中找出有多少人有车，有多少人有船，现在有多少人骑自行车等等

|   name   |   obj  |
---------------------
|  john    |  car   |
|  mary    |  boat  |
|  dave    |  car   |
|  james   |  bike  |
|  steve   |  car   |
|  walt    |  bike  |

例如:自行车 - 2

Answer 1

你可以使用这个查询

SELECT obj, COUNT(name) as nb FROM table GROUP BY obj ORDER BY obj

结果(sqlfiddle):

|   obj    |   nb   |
---------------------
|  bike    |    2   |
|  boat    |    1   |
|  car     |    3   |