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MySQL查询DISTINCT,COUNT

[英]MySQL query DISTINCT, COUNT

I'm trying to use a SELECT DISTINCT to find out how many people have cars, how many have boats, now many bikes and so on, from this table 我正在尝试使用SELECT DISTINCT从这张表中找出有多少人有汽车,有多少船,现在有很多自行车等。

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

ex: bike - 2 例如:自行车-2

You can use this query 您可以使用此查询

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

Result ( sqlfiddle ): 结果( sqlfiddle ):

|   obj    |   nb   |
---------------------
|  bike    |    2   |
|  boat    |    1   |
|  car     |    3   |
select sum(obj = 'car') as car_count,
       sum(obj = 'boat') as boat_count
from your_table

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