MySQL complex query statement, work in the record under

1 go to re-query

Select DISTINCT ID from User_info where xxxxxx

2 sorting in GROUP by grouping queries

The group by itself does not have a sort function, which is probably not the perfect place for MySQL, but we can do that

Select attack_id, Time from (SELECT * from Attack_log where (time+172800) < Unix_timestamp (now ()) Order by time Desc) a Ttack_log GROUP BY attack_id

* Note: first by sorting rows into a set, and then to change the collection to check, so that the grouping to achieve a sort of query

3 Finding the top two data that meets your requirements

Select Attack_id,time from Attack_log a where (select count (*) from attack_log where attack_id = a.attack_id and Time > A.time) <2

* Note: Where the back is actually a bool value. Filter compliant data with BOOL values

MySQL database migration (two songs)

1 mysqldump-uroot-p scbdb >>/home/zhangchuan/scbdb.sql (Generate SQL file for database to be migrated)

2 in MySQL environment source./scbdb.sql; (executes the statement in the MySQL environment of the target database)

It's so simple.

MySQL complex query statement, work in the record under