sql查询语句大全文库SQL query Daquan LibrarySQL query Daquan.Txt library to stay up late, because thecourage to end the day; stay in bed because of the courage tostart the day. Friend is who can see you and love you. SQL querystatement Daquan
Statement function
1, data manipulation
Select -- retrieving rows and columns from a database tableInsert -- adding new data rows to a database table
Delete -- deleting data rows from database tables
Update -- update the data in the database table
2, data definition
Create TABLE -- create a database table
Drop TABLE -- delete tables from the database
Alter TABLE -- modifying the structure of the database tableCreate VIEW - create a view
Drop VIEW -- delete views from the database
Create INDEX -- create an index for the database table
Drop INDEX -- delete index from database
Create PROCEDURE - creating a stored procedure
Drop PROCEDURE -- delete stored procedures from the databaseCreate TRIGGER - creating a trigger
Drop TRIGGER -- delete triggers from the database
Create SCHEMA -- add a new schema to the database
Drop SCHEMA - deletes a schema from the database
Create DOMAIN -- creating a data range
Alter DOMAIN - change domain definition
Drop DOMAIN -- deletes a domain from the database
3, data control
GRANT -- grant user access rights
DENY -- deny user access
REVOKE -- removing user access rights
4, transaction control
COMMIT - end the current transaction
ROLLBACK -- abort the current transaction
SET TRANSACTION -- defining the access characteristics ofcurrent transaction data
5, programmed SQL
DECLARE -- setting cursors for queries
EXPLAN -- description of data access plan for queriesOPEN - retrieve the query results and open a cursorFETCH -- retrieve a row of query results
CLOSE - close the cursor
PREPARE -- preparing SQL statements for dynamic executionEXECUTE -- dynamic execution of SQL statements
DESCRIBE - describe the prepared query
6, local variables
Declare @id char (10)
--set @id =' 10010001'
Select @id =' 10010001'
7, global variables
- must be at the beginning of @ @8, IF statement
Declare @x int @y int @z int
Select @x = 1 @y = 2 @z=3
If @x > @y
Print'x > Y'- print string'x > Y'Else if @y > @z
Print'y > z'
Else print'z > Y'
9, CASE statement
Use Pangu
Update employee
Set e_wage =
Case
When job_level = ' 1' then e_wage*1.08
When job_level = '2' then e_wage*1.07
When job_level = '3' then e_wage*1.06
Else e_wage*1.05
End
10, WHILE CONTINUE BREAK statement
Declare @x int @y int @c int
Select @x = 1 @y=1
While @x < 3
Begin
Print @x -- the value of the print variable xWhile @y < 3
Begin
Select @c =100*@x+ @y
Print @c -- the value of the print variable C
Select @y = @y + 1
End
Select @x = @x + 1
Select @y = 1
End
11, WAITFOR statement
The example waits for 1 hours, 2 minutes, 3 seconds to executethe Select statement
Waitfor delay '01:02:03'
从雇员中选择*
——例等到晚上11点零8分后才执行选择语句
等待时间的23:08:00”
从雇员中选择*
12、选择语句
选择* 列名从table_name 表名在col umn_name算子值例 宿主
SELECT * FROM stock_information哪里StockID中= str NIDs tockname = “str_name”
s tockname像“%发现这%stockname如[A-Za-z] % --------- [ ]指定值的范围s tockname喜欢[ ^调频] % --------- ^排除指定范围
---------只能在使用像关键字的哪里子句中使用通配符
或stockpath = “stock_path”
或sto cknumb er1000
和股票指数= 24
不stocksex = '人's tocknumber之间的20和100
在sto cknumb er 10、 20、 30
通过StockID中倒序ASC ---------排序 desc -降序 ASC升序由1,2 ---------通过列号秩序stockname = 选择从哪里stockname stock_information StockID中= 4
---------子查询
---------除非能确保内层选择只返回一个行的值
---------否则应在外层哪里子句中用一个在限定符
选择不同的c o lumn_name形式tab l e_name ---------不同指定检索独有的列值不重复
选择s tocknumber “s tocknumber + 10 + 10 = sto cknumb er从t ab l e_n ame
选择stockname “stocknumber” =数*从table_name组s tockname---------组将表按行分组指定列中有相同的值
具有计数* = 2 ---------具有选定指定的组
选择*
从表1表2
在table1. id * = tabl e2. id --------左外部连接表1中有的而表中没有得以空表示table1. id = * table2. id --------右外部连接
选择s tockname从表1
联盟[全部] -----联盟合并查询结果集全保留重复行
选择s tockname从表2
13、插入语句
插入tab l e_names toc k_names toc k_numb er值 “XXX” 、 “XXXX” 值选择stockname s tocknumber从stock_tabl e2 ---价值为选择语句
14、更新语句
更新tabl e_name集stockname = “XXX” [ 3 ]在Stock ID中=s tockname =默认stockname = nulls tocknumber = st ockname + 4
15、删除语句
删除从table_name哪里StockID中= 3
截断t ab l e_n ame -----------删除表中所有行仍保持表的完整性表t ab l e_nam e---------------完全删除表
16、 ALTER TABLE *** ---修改数据库表结构
修改表database.owner.table_name添加column_name char 2空. . . . .
raksmart作为一家老牌美国机房总是被很多人问到raksmart香港服务器怎么样、raksmart好不好?其实,这也好理解。香港服务器离大陆最近、理论上是不需要备案的服务器里面速度最快的,被过多关注也就在情理之中了。本着为大家趟雷就是本站的光荣这一理念,拿了一台raksmart的香港独立服务器,简单做个测评,分享下实测的数据,仅供参考!官方网站:https://www.raksmart.com...
中秋节快到了,spinservers针对中国用户准备了几款圣何塞机房特别独立服务器,大家知道这家服务器都是高配,这次推出的机器除了配置高以外,默认1Gbps不限制流量,解除了常规机器10TB/月的流量限制,价格每月179美元起,机器自动化上架,一般30分钟内,有基本自助管理功能,带IPMI,支持安装Windows或者Linux操作系统。配置一 $179/月CPU:Dual Intel Xeon E...
关于HostDare服务商在之前的文章中有介绍过几次,算是比较老牌的服务商,但是商家背景财力不是特别雄厚,算是比较小众的个人服务商。目前主流提供CKVM和QKVM套餐。前者是电信CN2 GIA,不过库存储备也不是很足,这不九月份发布新的补货库存活动,有提供九折优惠CN2 GIA,以及六五折优惠QKVM普通线路方案。这次活动截止到9月30日,不清楚商家这次库存补货多少。比如 QKVM基础的五个方案都...