Mysql left jion: that is, left outer join (same as right join), jionouter

Mysql left jion: that is, left outer join (same as right join), jionouter

Left Outer Join:

A left jion B on A. id = B. id indicates that the data in Table A does not move. After adding the data in Table B to table A corresponding to Table

Outer right connection:

Rignt jion is to add A to B, B does not move, save all.

Left jion is left outer join, short.

Example:

Select *
From app_id_gx7 left outer join ad_network_app
On app_id_gx7.app_id = ad_network_app.app_id
Where ad_network_app.ad_network_id = 5

Tested whether the OUTER effect is the same.