July 2018
Intermediate to advanced
558 pages
17h 1m
Chinese
Content preview from SQL经典实例
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/* 非Null值COMM升序排列，全部Null值放到最前面 */
1 select ename,sal,comm
2 from emp
3 order by comm nulls first
ENAME SAL COMM
------ ----- ----------
SMITH 800
JONES 2975
CLARK 2450
BLAKE 2850
SCOTT 3000
KING 5000
JAMES 950
MILLER 1300
FORD 3000
ADAMS 1100
TURNER 1500 0
ALLEN 1600 300
WARD 1250 500
MARTIN 1250 1400
/* 非Null值COMM降序排列，全部Null值放到最前面 */
1 select ename,sal,comm
2 from emp
3 order by commdesc nulls first
ENAME SAL COMM
------ ----- ----------
SMITH 800
JONES 2975
CLARK 2450
BLAKE 2850
SCOTT 3000
KING 5000
JAMES 950
MILLER 1300
FORD 3000
ADAMS 1100
MARTIN 1250 1400
WARD 1250 500
ALLEN 1600 300
TURNER 1500 0
3.
讨论
除非数据库管理系统提供了一种方式，它能够让你在无须修改非 ...
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.