- insert into Table1(Name,des,num) values ('ltp','thisisbest',10);
- select @@identity as 'Id'
2.實(shí)現(xiàn)是1或0想顯示為男或女
- select name,Sex=
- case Sex
- when '1' then '男'
- when '0' then '女'
- end
- from Tablename
3.嵌套子查詢
- select a,b,c from Table1 where a IN (select a from Table2)
4.顯示文章、提交人和最后回復(fù)時(shí)間
- select a.title,a.username,b.adddate
- from tablename a,(select max(adddate) adddate from tablename where
- tablename.title=a.title) b
5.隨機(jī)提取條記錄的例子
- SQL Server:Select Top 10 * From Tablename Order By NewID()
- Access:Select Top 10 * From Tablename Order By Rnd(ID)
-
- Rnd(ID) 其中的ID是自動(dòng)編號(hào)字段,可以利用其他任何數(shù)值來完成,
比如用姓名字段UserName)
- Select Top 10 * From 表Order BY Rnd(Len(UserName))
- MySql:Select * From 表Order By Rand() Limit 10
6.在同一表內(nèi)找相同屬性的記錄
- select UserID from Accounts_Users
- where UserName is not null
- group by UserID
- having count (*)>1
7.查詢類別所有的產(chǎn)品對(duì)應(yīng)數(shù)據(jù)
- SELECT CategoryName,ProductName
- FROM Categories LEFT JOIN Products
- ON Categories.CategoryID = Products.CategoryID;
8.按范圍查詢編號(hào)在2到5之間的用戶信息
- select * from UserValue where UserID between 2 and 5
9.日程安排提前5分鐘提醒
- Select * from TabSchedule where datediff(minute,getdate(),開始時(shí)間)<5
10.得出某日期所在月份的最大天數(shù)
- SELECT DAY(DATEADD(dd, -DAY('2008-02-13'),DATEADD(mm, 1,
'2008-02-13')))
- AS 'DayNumber'
11.按姓氏筆畫排序
- Select * From TableName Order By CustomerName Collate
Chinese_PRC_Stroke_ci_as
12.通配符的一些用法
- 1select * from tablename where column1 like '[A-M]%'
- 這樣可以選擇出column字段中首字母在A-M之間的記錄
- 2select * from tablename where column1 like '[ABC]%'
- 這樣可以選擇出column字段中首字母是A或者B或者C的記錄
- 3select * from tablename where column1 like '[A-CG]%'
- 這樣可以選擇出column字段中首字母在A-C之間的或者是G的記錄
- 4select * from tablename where column1 like '[^C]%'
- 這樣可以選擇出column字段中首字母不是C的記錄
- 單字符(關(guān)鍵字:like _):
- 通過使用下滑線字符(_),可以匹配任意單個(gè)字符
- select * from tablename where column1 like 'M_crosoft'
- 匹配特殊字符:([ ] _ - %)
- 把它們都放到[]中就行了,比如:
- select * from tablename where column1 like '%[%]%'
13.復(fù)制表結(jié)構(gòu)(只復(fù)制結(jié)構(gòu),源表名:a,目標(biāo)表名:b)
- select * into b from a where 1<>1
- 或
- select top 0 * into [b] from [a]
14.復(fù)制表數(shù)據(jù)(復(fù)制數(shù)據(jù),源表名:a,目標(biāo)表名:b)
- insert into b(Name,des,num) select Name,des,num from Table1;
15.編輯一個(gè)列
- 增加列:
- alter table Table1 add username varchar(30) not null default ''
- 修改列:
- alter table Table1 alter column username varchar(40)
- 刪除列:
- alter table Table1 drop column username
16.修改時(shí)間字段的小時(shí)部分
--把所有時(shí)間2006-11-1的數(shù)據(jù) 23點(diǎn) 修改為 21點(diǎn)
- update Ad_Browse_20061101
- set browsetime='2006-11-01 21'+
- SUBSTRING(CONVERT(VARCHAR(30),browsetime,8),3,7)
- where DATEPART(Hour,browsetime)=23
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