oracle一些笔记

1.字符串类型字段 区分大小写 where table_name = 'MIDDLE'

2.execute immediate '' bulk collect into v_xxx_tab    

3.列别名不加引号  select count(1)   计数

4.select  distinct   max(personincome) over   (partition by  earnmonth, earn)  from earnings  需要加distinct 。这里的 partition by不同于 group by

5.order by null  last    / null first