生成GUID：
sys_guid()
分页显示：
SELECT * FROM 表名 WHERE ROWNUM BETWEEN #{起始条数}+1 AND #{结束条数}
查询字段所在表：
select column_name,table_name from user_tab_columns where column_name='字段名'
查询表所有字段：
SELECT COLUMN_NAME FROM DBA_TAB_COLUMNS WHERE TABLE_NAME = '表名' ORDER BY COLUMN_ID
