oracle中，改变表名和字段名的大小写

1.将表名和字段名改为大写  见--http://www.cnblogs.com/wenboge/articles/4121331.html

2.将表名和字段名改为小写

①改表名为小写

begin
   for c in (select table_name tn from user_tables where table_name <> lower(table_name)) loop
       begin
          execute immediate ‘alter table ‘||c.tn||‘ rename to "‘||lower(c.tn)||‘"‘;
       exception
          when others then
             dbms_output.put_line(c.tn||‘已存在‘);
       end;
   end loop;
end;

②改字段名为小写

begin
  for t in (select table_name tn from user_tables) loop
      begin
         for c in (select column_name cn from user_tab_columns where table_name=t.tn) loop
             begin
                execute immediate ‘alter table ‘||t.tn||‘ rename column ‘||c.cn||‘ to "‘||lower(c.cn)||‘"‘;
             exception
                when others then
                   dbms_output.put_line(t.tn||‘.‘||c.cn||‘已经存在‘);
             end;
         end loop;
      end;
  end loop;
end;

注：

1.如果字段和表名都要改为小写，先改字段，再改表。

2.如果表名获取字段名改为小写以后，要在查询语句中将表名和字段名都要加上双引号

例.

　表名小写 ：select * from "department";

字段名小写：select "id" from "department";

我也不知道为啥这样