Answers for "difference between left join and left outer join"

difference between inner join vs outer join

INNER JOIN:
is used when retrieving data from multiple
tables and will return only matching data.

LEFT OUTER JOIN:
is used when retrieving data from
multiple tables and will return
left table and any matching right table records.

RIGHT OUTER JOIN:
is used when retrieving data from
multiple tables and will return right
table and any matching left table records

FULL OUTER JOIN:
is used when retrieving data from
multiple tables and will return both
table records, matching and non-matching.

right outer vs left outer join

LEFT OUTER JOIN:
is used when retrieving data from
multiple tables and will return
left table and any matching right table records.

RIGHT OUTER JOIN:
is used when retrieving data from
multiple tables and will return right
table and any matching left table records

Perform a left outer join of self and other.

x = sc.parallelize([("a", 1), ("b", 4)])
y = sc.parallelize([("a", 2)])
sorted(x.leftOuterJoin(y).collect())
# [('a', (1, 2)), ('b', (4, None))]