oracle一次给表添加多个字段

DECLARE
  V_SQL        VARCHAR2(2000);
  V_TABLE_NAME VARCHAR2(30);
  CURSOR C1 IS
    SELECT TABLE_NAME FROM USER_TABLES;   --查询当前用户下的所有表
BEGIN
  OPEN C1;
  LOOP
    --提取一行数据到c1
    FETCH C1
      INTO V_TABLE_NAME;
    --判读是否提取到值，没取到值就退出
    --取到值c_job%notfound 是false 
    --取不到值c_job%notfound 是true
    EXIT WHEN C1%NOTFOUND;
    V_SQL := ‘alter table ‘ || V_TABLE_NAME || ‘ add BATCHDATE NUMBER(8,0)‘;
    EXECUTE IMMEDIATE V_SQL;
    V_SQL := ‘alter table ‘ || V_TABLE_NAME ||
             ‘ add SOURCE_ID  NUMBER(8,0)‘;
    EXECUTE IMMEDIATE V_SQL;
    V_SQL := ‘alter table ‘ || V_TABLE_NAME || ‘ add load_date date‘;
    EXECUTE IMMEDIATE V_SQL;
  END LOOP; --关闭游标
  CLOSE C1;
END;