As shown in the figure, these two results are obtained from select queries. How to join them and merge them?
大家讲道理2017-05-25 15:10:05
The union fields must be the same. You can add a field (number of people entering the site) to the result of the first picture as 0. The
sql statement is as follows (select time_start, time_end,0 as num from table) union
(select time_start, time_end, num from table );
num refers to the number of people entering the station