两个表循环取第一条

declare
r_return varchar2(200);
v_sql varchar2(10000);
CURSOR C_AGE IS select distinct usagename from dictusage;
CURSOR C_AGE1 IS select * from dictusage;
begin
v_sql:='';
FOR R_DT IN C_AGE LOOP
FOR R_DT1 IN C_AGE1 LOOP
if R_DT.usagename= R_DT1.usagename then
v_sql:=v_sql||','||R_DT1.usageid||'';
exit;
end if;

end loop;
END LOOP;
dbms_output.put_line(v_sql);
end;