how to remove duplicate entries on a single column and get all corresponding column values by AWK

Question

how to remove duplicate entries on a single column and get all corresponding column values using AWK

my data input

100	test
100	test
200	cool
300	bold
300	bold

need below output

100	test
200	cool
300	bold

Answer 1

awk -F'\t' '!a[$1]++ {print $1,$2}' filename