mysql - How to connect two select results in sql statement?

Question

As shown in the figure, these two results are obtained from the select query. How to join them together?

PHP中文网 · Answer

<p>UNION</p>

大家讲道理 · Answer

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