Given two data frames:
df1 = data.frame(CustomerId = c(1:6), Product = c(rep("Toaster", 3), rep("Radio", 3)))
df2 = data.frame(CustomerId = c(2, 4, 6), State = c(rep("Alabama", 2), rep("Ohio", 1)))
df1
# CustomerId Product
# 1 Toaster
# 2 Toaster
# 3 Toaster
# 4 Radio
# 5 Radio
# 6 Radio
df2
# CustomerId State
# 2 Alabama
# 4 Alabama
# 6 Ohio
How can I do database style, i.e., sql style, joins? That is, how do I get:
- An inner join of
df1anddf2:
Return only the rows in which the left table have matching keys in the right table. - An outer join of
df1anddf2:
Returns all rows from both tables, join records from the left which have matching keys in the right table. - A left outer join (or simply left join) of
df1anddf2
Return all rows from the left table, and any rows with matching keys from the right table. - A right outer join of
df1anddf2
Return all rows from the right table, and any rows with matching keys from the left table.
Extra credit:
How can I do a SQL style select statement?