，请问如何可以用一条语句查询失败率

Question

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+-----------------+--------+-------+-------------+--------------+--------------+--------------+-----------+---------------+---------------+
| 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 |
+-----------------+--------+-------+-------------+--------------+--------------+--------------+-----------+---------------+---------------+

Answer 1

select interface_name,sum(if(status=0,1,0))/count(*)
from test group by interface_name

Answer 2

谢谢wwwb的回答，请问这句话是什么意思？
sum(if(status=0,1,0))

Answer 3

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

Answer 4

sum(if(status=0,1,0))换成count(if(status=0,1,0))一样

Answer 5

那为什么是3个参数if(status=0,1,0)？
谢谢。

Answer 6

如果status=0，返回1，否则返回0