Try this:
awk -F"," '{print $1}' data.txt
It will split each input line in the file data.txt into different fields based on , character (as specified with the -F) and print the first field (column) to stdout.
Try this:
awk -F"," '{print $1}' data.txt
It will split each input line in the file data.txt into different fields based on , character (as specified with the -F) and print the first field (column) to stdout.