1.查询
SELECT * FROM rs_cxc_house_data t
2.获取前几条
SELECT * FROM rs_cxc_house_data t where rownum<=10
3.去重
SELECT distinct t.arch_no FROM rs_cxc_house_data t
4.日期转字符串格式
SELECT to_char(h.post_date,'yyyy-mm-dd')mdata FROM rs_cxc_house_data h
显示将post_date的日期值2019/12/17 6:57:00转换为2019-12-17
5.
