mysql> select * from table1;+----------+------------+-----+---------------------+| name_new | transactor | pid | order_date |+----------+------------+-----+---------------------+| 1hahha | 1xiaohong | 1 | 2019-08-04 20:45:47 || 2hahha | 2xiaohong | 2 | 2019-08-04 20:45:57 || 3hahha | 3xiaohong | 3 | 2019-08-04 20:46:02 || 4hahha | 4xiaohong | 4 | 2019-08-04 20:46:05 || 3hahha | bob | 5 | 2019-08-04 20:46:08 || 3hahha | lee | 6 | 2019-08-04 20:46:12 || 3hahha | lee | 7 | 2019-08-04 21:56:01 || 3hahha | lee | 8 | 2019-08-04 21:56:10 || 3hahha | bob | 9 | 2019-08-04 21:56:18 || 3hahha | bob | 10 | 2019-08-04 21:56:26 |+----------+------------+-----+---------------------+10 rows in set (0.00 sec)mysql> select count(*) as count,max(pid) as maxpid,min(pid) as minpid,avg(pid) as avgpid from table1;+-------+--------+--------+--------+| count | maxpid | minpid | avgpid |+-------+--------+--------+--------+| 10 | 10 | 1 | 5.5000 |+-------+--------+--------+--------+1 row in set (0.00 sec)