How to Merge Uneven Data Frames With Real Data - r

Question

Problem:
I have two different size data sets that I would like to merge together. Without abandoning rows or inserting NA's. To compare this to a excel document situation you would have five columns and you would drago down 3 of them to populate the blank space left by the rows inserted by adding your data to the 4th and 5th column.
Example Data Set
zipcode = a, step3 = b in my later brainstorming code to solve my problem
> head(zipcode_joincsv)
zip city abv latitude longitude median mean pop
226 01749 Hudson AL 42.38981 -71.55791 76500 85689 18081
227 01752 Marlborough AL 42.35091 -71.54753 71835 89002 36273
228 01754 Maynard AL 42.43078 -71.45594 76228 82167 10414
229 01756 Mendon AL 42.09201 -71.54474 102625 117692 5257
230 01757 Milford AL 42.14918 -71.52149 68565 82206 26877
231 01760 Natick AL 42.29076 -71.35368 90673 113933 31763
> head(step3_df)
tolower.state.name. state.abb
1 alabama AL
2 alaska AK
3 arizona AZ
4 arkansas AR
5 california CA
6 colorado CO
Desired Result:
One DF where each zipcode city combo is combined with their states pop and
income. A column in common they have is the abbreviation column.
tolower.state.name. zip city abv latitude longitude median mean pop
1 alabama 01749 Hudson AL 42.38981 -71.55791 76500 85689 18081
2 alabama 01752 Marlborough AL 42.35091 -71.54753 71835 89002 36273
3 alabama 01754 Maynard AL 42.43078 -71.45594 76228 82167 10414
4 alabama 01756 Mendon AL 42.09201 -71.54474 102625 117692 5257
5 alabama 01757 Milford AL 42.14918 -71.52149 68565 82206 26877
6 alabama 01760 Natick AL 42.29076 -71.35368 90673 113933 31763
7 alaska data from these rows
8 arizona data from these rows
9 arkansas data from these rows
10 california data from these rows
11 colorado data from these rows
I've contemplated using something like
sqldf ("SELECT a.Zip, a.City, a.State Abv, a.Lat, a.Long, a.median, a.mean, a.pop, b.state.name, b.states.abb, b.pop, b.income
FROM a a
LEFT JOIN b b using (abv)")
I know that is probably not going to work if only that if it worked all the rows that there was not a matching set from A would input a NA where what I would like is that for every abv of NY the states average income and total population gets copied down the line. Than for every AR and every AL etc until the two data sets are one that a ggplot using all of the data can be created.

Answer 1

dplyr::left_join(a, b, by="abv") should work.