版权声明:本文为博主原创文章,未经博主允许不得转载。 https://blog.csdn.net/lyh1234/article/details/81271265
有如下设备信息表:
要求按status统计数量,查询结果返回一条数据,如下图所示:
可是使用如下SQL语句:
SELECT
COUNT(*) AS total,
SUM(IF(status = 1, 1, 0)) AS status1,
SUM(IF(status = 2, 1, 0)) AS status2,
SUM(IF(status = 3, 1, 0)) AS status3,
SUM(IF(status = 4, 1, 0)) AS status4
FROM
dev_device_info