SELECT COUNT(*) AS count FROM sys_user WHERE username LIKE CONCAT('%','d','%')
2.查找某人
SELECT * FROM sys_user WHERE username = 'admin'
3.子查询组合
SELECT t1.count,t2.* FROM(
SELECT COUNT(*) AS count FROM sys_user WHERE username LIKE CONCAT('%','d','%')
) t1,
(
SELECT * FROM sys_user WHERE username = 'admin'
) t2
子查询就可以
1.统计人数
2.查找某人
3.子查询组合