How to assign a unique ID number to each group of identical values in a column?

[koya]

?my data:

accname

=======

abc

abc

xyz

abc

def

xyz

def

desired output:

accname         uniqid

=======        =====

abc                    1

abc                    1

xyz                    2

abc                    1

def                     3

xyz                    1

def                     3

[mohamed_zaki]

proc sort data=have;

by accname;

run;

data want;

set have;

by accname;

retain order 0;

if first.accname then order=order+1;

run;