实用SQL语句总结
| id | name |
| 1 | a |
| 2 | b |
| 3 | c |
| 1 | a |
| 2 | b |
| 3 | c |
以下的sql语句都以上面表mytable为准:
1、查询id=1,3记录的所有数据
select * from mytable
where id in(1,3)
where id in(1,3)
2、删除id重复的数据，表中数据只剩下id=1,2,3的所有数据
select * into # from mytable
truncate table mytable
insert mytable select distinct * from #
select * from mytable
drop table #
truncate table mytable
insert mytable select distinct * from #
select * from mytable
drop table #
3、创建一个新表 films_recent ，它的值包含来自表films
SELECT * INTO films_recent FROM films
4、列出数据库里所有的表名
select name from sysobjects where type='U'
5、输出当前时间戳
PRINT @@DBTS
6、按月统计并排序
select count(id) as sum, datename(year, AddTime) as year, datename(month, AddTime) as month from visitindex group by datename(year, AddTime) , datename(month, AddTime) order by datename(year, AddTime) desc, datename(month, AddTime) desc
7、按年统计
select count(id) as sum, datename(year, AddTime) as year from visitindex group by datename(year, AddTime) order by datename(year, AddTime) desc
8、绝对值
select abs(-1) value from dual
9、取整(大)
select ceil(-1.001) value from dual
10、取整（小）
select floor(-1.001) value from dual
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全部评论:
 Queenie | 2016/6/13 18:46:00 |
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| blade and soul gold | 2016/1/13 4:27:00 |
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感谢以下网友对网站提出的建议：
1、感谢“蓝树叶kiss”网友发现一个评论漏洞。(2009-2-28)
2、感谢“陈臣”对程序优化和seo方面的建议。(2009-3-18)
请稍侯......
