oracle空串比较
declare len_x integer; len_y integeoracle账号r; begin select nvl(length(trim('')), 0) into len_x from dual; select nvl(length(trim(null)), 0) into len_y from dual; dbms_output.put_line('len_x=' || len_x); dbms_output.put_line('len_y=' || len_x); if len_x = len_y then dbms_output.put_line('1111'); else dbms_output.put_line('2222'); end if; end;