Left-outer join queries

A left-outer join query returns all the rows from the left table, not just the ones in which the joined column match.

If a row in the left table has no matching rows in the right table, the associated result row contains nulls for all select clause columns that come from the right table:

MYDB.SCHEMA(USER)=> SELECT * FROM weather LEFT OUTER JOIN cities ON 
(weather.city = cities.name);