Ignore case when removing duplicates using awk

Question

I am using following command to remove duplicates from file.

awk -F"," '!x[$1]++' test.csv

How can I make it to ignore case of column 1?

I tried awk -F"," '{IGNORECASE = 1} !x[$1]++' test.csv but it does not seem to work.

Answer 1

Using toupper:

awk -F"," '!x[toupper($1)]++' test.csv