I have the following two data frames which have just one column each and have exact same number of rows. How do I merge them so that I get a new data frame which has the two columns and all rows from both the data frames. For example,

df1:

+-----+
| ColA|
+-----+
|    1|
|    2|
|    3|
|    4|
+-----+

df2:

+-----+
| ColB|
+-----+
|    5|
|    6|
|    7|
|    8|
+-----+

I want the result of the merge to be

df3:

+-----+-----+
| ColA| ColB|
+-----+-----+
|    1|    5|
|    2|    6|
|    3|    7|
|    4|    8|
+-----+-----+

I don't quite see how I can do this with the join method because there is only one column and joining without any condition will create a cartesian join between the two columns. Is there a direct SPARK Data Frame API call to do this? In R Data Frames, I see that there a merge function to merge two data frames. However, I don't know if it is similar to join.

Thanks,

Bhaskar