单个查：select sum(vsize(EMPNO)) from EMP t
使用游标查：
declare
v_var2 number;
cursor p_cursor is select column_name from user_tab_columns t where table_name='EMP';
t_row p_cursor%rowtype;
begin
v_var2 :=0;
for t_row in p_cursor loop
if v_var2=0 then
select sum(vsize(t_row.column_name)) into v_var2 from emp;
dbms_output.put_line(t_row.column_name||' '||v_var2);
end if;
v_var2 :=0;
end loop;
end;
结果怎么就不一样呢？
使用游标查：
declare
v_var2 number;
cursor p_cursor is select column_name from user_tab_columns t where table_name='EMP';
t_row p_cursor%rowtype;
begin
v_var2 :=0;
for t_row in p_cursor loop
if v_var2=0 then
select sum(vsize(t_row.column_name)) into v_var2 from emp;
dbms_output.put_line(t_row.column_name||' '||v_var2);
end if;
v_var2 :=0;
end loop;
end;
结果怎么就不一样呢？
