This is not an Excel feature, although it should be! Often times we have a list of things in a column that needs to be combined into, say, a comma-delimited string. Column to Text in R…
Column to Text in Excel
That column looks like this:
Typically I write a quick formula that cumulatively concacatenates the rows, something like this:
That last cell is what I want. Usually it’s to plug it into a SQL query or something.
Column to Text in R
This is super easy in R. Always remembering that a dataframe column is actually just a vector, we can use the
paste() function which is used for combining strings.
# print the column vector just to check col length(col)
 156863 141205 481808 515823 648410 656289 900801  7
There we see
col is a vector of seven numbers.
# collapse the col vector into a string string = paste(col, collapse = ", ") string length(string)
 "156863, 141205, 481808, 515823, 648410, 656289, 900801"  1
And there you see that after we apply the
paste() function with
collapse, we get a vector with one single value, and that value is a comma-separated string of customer IDs.
Now that string can be plugged into a SQL query or elsewhere.
Deduping that list
If we do need this for a SQL query (like a
WHERE clause), we should probably remove duplicates. R really starts to shine here compared to Excel.
unique(col) into the
paste() function instead:
# collapse the col vector into a string string = paste(unique(col), collapse = ", ")
As with all nested functions, read from inside-out. First we get a unique vector of
col values, and then we plug that into