VA Joins Flashcards
1
Q
Inner Join
A
- rows that are in both tables
2
Q
Left Join
A
- rows that are in left table & matched records from right table or NAN
3
Q
Right Join
A
- rows that are in right table & matched records from left table or NAN
4
Q
Outer (Full) Join
A
- all rows from both tables (many NAs)
5
Q
Cross Join
A
- paired combination of each row of table 1 with each row of table 2
- all possibilities
- no NAs
6
Q
Inner Join vs Intersection
A
- INNER JOIN: returns duplicates, never return NULL
- INTERSECT: removes duplicates, will return NULL
