日期:2014-05-16  浏览次数:21215 次

,请问如何可以用一条语句查询失败率
表test结构如下,其中status=1表示成功,status=0表示失败,请问如何可以用一条语句查询到每个interface_name的失败率
SQL code

+-----------------+--------+-------+-------------+--------------+--------------+--------------+-----------+---------------+---------------+
| interface_name  | status | count | avg_latency | slow_count_1 | slow_count_2 | slow_count_3 | client_id | ip            | timestamp     |
+-----------------+--------+-------+-------------+--------------+--------------+--------------+-----------+---------------+---------------+
| /email/exist    |      1 |     1 |         246 |            1 |            1 |            0 | 111111    | 127.0.0.1     | 1349689181769 |
| hasProfileUser  |      0 |   100 |          50 |           30 |           20 |           10 | 111111    | 192.168.10.22 |       1234567 |
| hasProfileUser  |      1 |   100 |          50 |           30 |           20 |           10 | 111111    | 192.168.10.22 |       1234567 |
| hasProfileUser1 |      1 |   100 |          50 |           30 |           20 |           10 | 111111    | 192.168.10.22 |       1234567 |
| hasProfileUser2 |      1 |   100 |          50 |           30 |           20 |           10 | 111111    | 192.168.10.22 |       1234567 |
+-----------------+--------+-------+-------------+--------------+--------------+--------------+-----------+---------------+---------------+




------解决方案--------------------
select interface_name,sum(if(status=0,1,0))/count(*)
from test group by interface_name
------解决方案--------------------
if(status=0,1,0):如果status=0,取值1,
sum:计算出1的总数,即status=0的总数
------解决方案--------------------
sum(if(status=0,1,0))换成count(if(status=0,1,0))一样
------解决方案--------------------
如果status=0,返回1,否则返回0