Outer
Join:
Records
which will not join with the other record set are still included in the result
Left Outer:
Records
from the first data set are included whether they have a match or not.Fields
from the unmatched bag are set to null.
use the datasets from inner join tutorial
use the datasets from inner join tutorial
Code:
Userinfo_leftouter
= join aa BY user left outer,bb BY user;
Output:
User
1,user 2 and user 5 have matches ,it shows concatenated results.User 4 does not
any match in bb,so the bb part has null values. User 3 in bb is not displayed
at all.
Right Outer:
The
opposite to the left outer join. Records from the second data set are included
no matter what. Fields from unmatched bag are set to null.
Code:
Userinfo_leftouter
= join aa BY user right outer,bb BY user;
Output:
Full Outer:
Records
from both sides are included.For unmatched records the fields from the other
bag are set to NULL.
Code:
Userinfo_leftouter
= join aa BY user full outer,bb BY user;
Output:
Summary: