//取得数据表相应信息的SQL语句
select t.TABLE_NAME  as 表名,
       t.COLUMN_NAME as 列表,
       t.DATA_TYPE   as 列数据类型,
       t.DATA_LENGTH as 列数据长度
  from user_tab_columns t
 where t.TABLE_NAME = :tableName

 
  select s.table_name as 表名,
         s.comments as 表注释
    from user_tab_comments s
   where s.table_name = :tableName



select y.table_name  as 表名,
       y.column_name as 字段名,
       y.comments    as 字段注释
  from user_col_comments y
 where y.table_name = :tableName