Postgres function to give first n prime numbers in SQL.

primes.sql

create or replace function primes(n int) 
returns setof int as $$
declare
    i integer := 2;
    p integer := 0;
    j integer := 0;
begin
    while i <= n loop
        j := floor(sqrt(i));
        p := 1;
        while j > 1 loop
            if i % j = 0 then
                p := 0
                exit;
            end if;      
            j := j-1;
        end loop;
        if p = 1 then 
            return next i;                  
        end if;
        i = i+1;
    end loop;
end; 
$$ LANGUAGE plpgsql;