postgresql partition by list with non primary key not working - insufficient columns in PRIMARY KEY constraint definition

Question

create table employeedata( id varchar(20) primary key, department varchar(20), salary integer, designation varchar(20) ) partition by list (department);

but i am getting following error

ERROR: insufficient columns in PRIMARY KEY constraint definition DETAIL: PRIMARY KEY constraint on table "employeedata" lacks column "department" which is part of the partition key. SQL state: 0A000

Am i doing anything wrong please help

I want to create table employee data and partition by departement column so i can get all employee of particular department in partition