sql - Creating Custom columns in stored procedure postgres -

i using stored procedure return type of student enrolled @ college. pushing id through should return first name , last name in new column going made(ex: commuter, employee, resident). keep getting error:

error:  syntax error @ or near "if" line 8:     if exists (select count(commuterid) > 0 commuter wh...). 

any tips or ideas?

create or replace function roleatmarist(int, refcursor) returns refcursor $$ declare    identifier      int := $1;    resultset refcursor := $2;  begin   open resultset     if exists (select count(commuterid) > 0 commuter commuterid = identifier)       select fname, lname, "commuter" role       people        peopleid = identifier;     end if;      if exists (select count(employeeid) > 0 employee emplpoyeeid = identifier)       select fname, lname, "employee" role       people        peopleid = identifier;     end if;      if exists (select count(residentid) > 0 studentpark residentid = identifier)       select fname, lname, "resident" role       people        peopleid = identifier;     end if; return resultset; end;  $$ language plpgsql;  select roleatmarist(12, 'resultset') ; fetch results ; 

this backwards in multiple ways. cursor use valid sql , no plpgsql commands. don't need cursor nor plpgsql begin with. simple sql function should do:

create or replace function role_at_marist(_identifier int)   returns table (fname text, lname text, "role" text) $func$    select p.fname, p.lname, text 'commuter'      people      p.peopleid = $1    ,    exists (select 1 commuter c c.commuterid = p.peopleid)     union    select p.fname, p.lname, 'employee'      people      p.peopleid = $1    ,    exists (select 1 employee e e.emplpoyeeid = p.peopleid)     union    select p.fname, p.lname, 'resident'      people      p.peopleid = $1    ,    exists (select 1 studentpark s s.residentid = p.peopleid) $func$ language sql;  

call:

select * role_at_marist(12); 

set-returning functions can used tables in from list.
string literals enclosed in single quotes!