MySQL sub-table records query related records of the same user in different log tables. That is, multi-table query, no association conditions

(select count(id) as num from con_logs_2018_01_10 where uid = '12081427281340000' )
union all
(select count(id) as num from con_logs_2018_01_09 where uid = '12081427281340000')

After the log is divided into tables, the logging information of the user needs to be counted , you need to query multiple sub-tables, but there is no relationship