difference between left join and left outer join code example
Example 1: 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.
Example 2: 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())
Example 3: 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