SQL里最基本的语法是什么呢-

一.SELECT语句的完整语法为：

SELECT[ALL|DISTINCT|DISTINCTROW|TOP]

{*|talbe.*|[table.]field1[AS alias1][,[table.]field2[AS alias2][,…]]}

FROM tableexpression[,…

][IN externaldatabase]

[WHERE…]

[GROUP BY…]

[HAVING…]

[ORDER BY…]

[WITH OWNERACCESS OPTION]

说明：

用中括号([])括起来的部分表示是可选的，用大括号({})括起来的部分是表示必须从中选择其中的一个。

一. 1 FROM子句

FROM子句指定了SELECT语句中字段的来源。FROM子句后面是包含一个或多个的表达式(由逗号分开)，其中的表达式可为单一表名称、已保存的查询或由 INNER JOIN、LEFT JOIN 或 RIGHT JOIN 得到的复合结果。如果表或查询存储在外部数据库，在IN 子句之后指明其完整路径。

例：下列SQL语句返回所有有定单的客户：

SELECT OrderID,Customer.customerID

FROM Orders Customers

WHERE Orders.CustomerID=Customers.CustomeersID

一．2 ALL、DISTINCT、DISTINCTROW、TOP谓词

(1) ALL 返回满足SQL语句条件的所有记录。如果没有指明这个谓词，默认为ALL。

例：SELECT ALL FirstName,LastName

FROM Employees

(2) DISTINCT 如果有多个记录的选择字段的数据相同，只返回一个。

(3) DISTINCTROW 如果有重复的记录，只返回一个

(4) TOP显示查询头尾若干记录。也可返回记录的百分比，这是要用 TOP N PERCENT子句（其中N 表示百分比）

例：返回5%定货额最大的定单

SELECT TOP 5 PERCENT*

FROM [ Order Details]

ORDER BY UnitPrice*Quantity*(1-Discount) DESC

一．3 用 AS 子句为字段取别名

如果想为返回的列取一个新的标题，或者，经过对字段的计算或总结之后，产生了一个新的值，希望把它放到一个新的列里显示，则用AS保留。

例：返回FirstName字段取别名为NickName

SELECT FirstName AS NickName ,LastName ,City

FROM Employees

例：返回新的一列显示库存价值

SELECT ProductName ,UnitPrice ,UnitsInStock ,UnitPrice*UnitsInStock AS valueInStock

FROM Products

二 .WHERE 子句指定查询条件

二 . 1比较运算符

比较运算符 含义

= 等于

> 大于

= 大于等于

不等于

!> 不大于

!#1/1/96# AND OrderDate#96-1-1#

也可以表示为：

WHERE OrderDate>Datevalue(‘1/1/96’)

使用 NOT 表达式求反。

例：查看96年1月1日以后的定单

WHERE Not OrderDateQuantity

另一种方法是用 Microsof JET SQL 独有的 JNNER JOIN

语法：

FROM table1 INNER JOIN table2

ON table1.field1 comparision table2.field2

其中comparision 就是前面WHERE子句用到的比较运算符。

SELECT FirstName,lastName,OrderID,CustomerID,OrderDate

FROM Employees

INNER JOIN Orders ON Employees.EmployeeID=Orders.EmployeeID

注意：

INNER JOIN不能连接Memo OLE Object Single Double 数据类型字段。

在一个JOIN语句中连接多个ON子句

语法：

SELECT fields

FROM table1 INNER JOIN table2

ON table1.field1 compopr table2.field1 AND

ON table1.field2 compopr table2.field2 OR

ON table1.field3 compopr table2.field3

也可以

SELECT fields

FROM table1 INNER JOIN

（table2 INNER JOIN [( ]table3

[INNER JOER] [( ]tablex[INNER JOIN]

ON table1.field1 compopr table2.field1

ON table1.field2 compopr table2.field2

ON table1.field3 compopr table2.field3

外部连接返回更多记录，在结果中保留不匹配的记录，不管存不存在满足条件的记录都要返回另一侧的所有记录。

FROM table [LEFT|RIGHT]JOIN table2

ON table1.field1comparision table.field2

用左连接来建立外部连接，在表达式的左边的表会显示其所有的数据

例：不管有没有定货量，返回所有商品

SELECT ProductName ,OrderID

FROM Products

LEFT JOIN Orders ON Products.PrductsID=Orders.ProductID

右连接与左连接的差别在于：不管左侧表里有没有匹配的记录，它都从左侧表中返回所有记录。

例：如果想了解客户的信息，并统计各个地区的客户分布，这时可以用一个右连接，即使某个地区没有客户，也要返回客户信息。

空值不会相互匹配，可以通过外连接才能测试被连接的某个表的字段是否有空值。

SELECT *

FROM talbe1

LEFT JOIN table2 ON table1.a=table2.c

四 .1 连接查询中使用Iif函数实现以0值显示空值

Iif表达式： Iif(IsNull(Amount,0,Amout)

例：无论定货大于或小于￥50，都要返回一个标志。

Iif([Amount]>50,?Big order?,?Small order?)

五 分组和总结查询结果

在SQL的语法里，GROUP BY和HAVING子句用来对数据进行汇总。GROUP BY子句指明了按照哪几个字段来分组，而将记录分组后，用HAVING子句过滤这些记录。

GROUP BY 子句的语法

SELECT fidldlist

FROM table

WHERE criteria

[GROUP BY groupfieldlist [HAVING groupcriteria]]

注：Microsoft Jet数据库 Jet 不能对备注或OLE对象字段分组。

GROUP BY字段中的Null值以备分组但是不能被省略。

在任何SQL合计函数中不计算Null值。

GROUP BY子句后最多可以带有十个字段，排序优先级按从左到右的顺序排列。

例：在‘WA’地区的雇员表中按头衔分组后，找出具有同等头衔的雇员数目大于1人的所有头衔。

SELECT Title ,Count(Title) as Total

FROM Employees

WHERE Region = ‘WA’

GROUP BY Title

HAVING Count(Title)>1

JET SQL 中的聚积函数

聚集函数 意义

SUM ( ) 求和

AVG ( ) 平均值

COUNT ( ) 表达式中记录的数目

COUNT (* ) 计算记录的数目

MAX 最大值

MIN 最小值

VAR 方差

STDEV 标准误差

FIRST 第一个值

LAST 最后一个值

六 用Parameters声明创建参数查询

Parameters声明的语法:

PARAMETERS name datatype[,name datatype[, …]]

其中name 是参数的标志符,可以通过标志符引用参数.

Datatype说明参数的数据类型.

使用时要把PARAMETERS 声明置于任何其他语句之前.

例:

PARAMETERS[Low price] Currency,[Beginning date]datatime

SELECT OrderID ,OrderAmount

FROM Orders

WHERE OrderAMount>[low price]

AND OrderDate>=[Beginning date]

七 功能查询

所谓功能查询,实际上是一种操作查询,它可以对数据库进行快速高效的操作.它以选择查询为目的,挑选出符合条件的数据,再对数据进行批处理.功能查询包括更新查询,删除查询,添加查询,和生成表查询.

七 .1 更新查询

UPDATE子句可以同时更改一个或多个表中的数据.它也可以同时更改多个字段的值.

更新查询语法:

UPDATE 表名

SET 新值

WHERE 准则

例:英国客户的定货量增加5%,货运量增加3%

UPDATE OEDERS

SET OrderAmount = OrderAmount *1.1

Freight = Freight*1.03

WHERE ShipCountry = ‘UK’

七 .2 删除查询

DELETE子句可以使用户删除大量的过时的或冗于的数据.

注:删除查询的对象是整个记录.

DELETE子句的语法:

DELETE [表名.*]

FROM 来源表

WHERE 准则

例: 要删除所有94年前的定单

DELETE *

FROM Orders

WHERE OrderData,,=)一起使用.返回一个布尔值True或False.ANY的意思是,表达式与子查询返回的一系列的值逐一比较,只要其中的一次比较产生True结果,ANY测试的返回 True值(既WHERE子句的结果),对应于该表达式的当前记录将进入主查询的结果中.ALL测试则要求表达式与子查询返回的一系列的值的比较都产生True结果,才回返回True值.

例:主查询返回单价比任何一个折扣大于等于25%的产品的单价要高的所有产品

SELECT * FROM Products

WHERE UnitPrice>ANY

(SELECT UnitPrice FROM[Order Details] WHERE Discount>0.25)

十 .2检查表达式的值是否匹配子查询返回的一组值的某个值

语法:

[NOT]IN(子查询)

例:返回库存价值大于等于1000的产品.

SELECT ProductName FROM Products

WHERE ProductID IN

(SELECT PrdoctID FROM [Order DEtails]

WHERE UnitPrice*Quantity>= 1000)

十 .2检测子查询是否返回任何记录

语法:

[NOT]EXISTS (子查询)

例:用EXISTS检索英国的客户

SELECT ComPanyName,ContactName

FROM Orders

WHERE EXISTS

(SELECT *

FROM Customers

WHERE Country = ‘UK’ AND

Customers.CustomerID= Orders.CustomerID)

用英语写一封信，题目是给英语老师的一封信，带翻译。怎么写？

几钱1分钟啊

更新2:

除咗去重新买卡

主要有2个方法： 1. 去7-11 or OK 买一张国际长途电话卡，面值通常有50

100

或者200。然后可用手机或者屋企电话根据卡背面的指示来打。通常都系拨打一个number之后会听到语音提示，只要跟住做就得。但系大陆不同的城市有不同的电话编号。我只知道上海是8621。价钱视乎不同的电话卡，一般（0.4 - 0.6 /min) 2. 如果你有安装SKYPE的话，可用Skype来打电话。价钱十分便宜（约0.16/min)，但是Skype要于网上用信用卡或者PPS预付费用。可参考：skype 希望可以帮到你啦~

thx

1. Check with your card supplier that the mobile phone can dial IDD. Then ask for the IDD code of the supplier. Then dial IDD code + 86 + area code of china region + tel .no. 2. Find a public phone

use coin

visa or octopus card to dial the number. 3. Contact you home telephone line supplier and ask them to connect the line for you and the money will be charged on your next bill. 4. Ask a friend to borrow his/her mobile phone/home line for you and you paid cash to them.( I have borow my lines to my relatives and friend before)

参考: personal experience

2角1分钟

你可以打掉03086769{电话号码 }

你要先打你已经注册左嘅电话商 (例如 1666

0060) 等等

之后就打86再打所属地区区号 ( 例如中山就要打760) 之后再打你要打嘅电话号码 例如) 1666-86-760-1234567 就系咁嘅

（急）高分请人帮汉译英（下面是原文）好的一定追加50分

My dear English teacher:\x0d\ From my English, I will contact a deeply like English. English let me open view, let me understand the culture of different region amorous feelings to.\x0d\ I want to use English freely and talk to people, but my spoken English is very bad.Language is a kind of habit, I find it hard to correct his poor pronunciation, this makes me very distressed, but I have worked very hard in the improved.\x0d\ I feel that learning English is the key to read more look more, I like reading comprehension, it not only let me get some knowledge, but also let me realize the happiness of learning English, I feel very proud can read English article.\x0d\ Thank you for teaching me. I believe in your teachings, I can certainly through their efforts to learn English well.\x0d\ Best wishes for you!\x0d\ Yours,nidemingzi \x0d\\x0d\敬爱的吴老师： \x0d\您好！不久，我已经踏上六年级的阶梯。吴老师，您为我们付出了许多汗水。今天我在这里和您谈谈心里话。 \x0d\您是一位关心学生的好老师。记得有一次，我班的一位同学由于身体不舒服，在课堂上有些头晕。当消息传到您的耳中时。您就叫那位学生扒在桌面上好好休息，给他一杯热水，还向他问寒问暖。 \x0d\还有一次，，您给我们讲课时，一会打哈欠，一会揉揉鼻子，我们都知道，我们都明白，是你的感冒使得你如此。我想：“吴老师，您怎么不在讲台上休息一会儿呢？”可是我知道，您是为了我们而在顽强地给我们讲课? \x0d\在将近期末考试的时候，老师比我们更为紧张，所以常常放学后多上一节课，给我们补课。有些学生埋怨老师不应该放学留下。但您不在乎听他们所讲的话。时时帮助不会的学生，教他们解决的方法，给他以容易的理解，让他能够明白。我们遇到不会的问题便向您请教，您也耐心地给予我们讲解。

Name: Gender: M

Marital status: single date of birth: May 5, 1985

National: Han height: 174cm

Education: Undergraduate residence: Jilin. Siping

Graduate school: Beijing University Humanities

Professional: Computer Application

Area are: Beijing's Tongzhou District

Language: Mandarin: Standard English: general

Work experience

2 years and a month's work experience

Customer demand for the patient but also a keen sense of

Proficiency: word, excel, Internet, etc.

The main work of the curriculum vitae:

In November 2006 to April 2007, working in the Beijing Electric Co., Ltd. Qingdao Camry

Work experience in detail:

In the senior school, approved by the school leadership, work-study program, working in Qingdao Camry Beijing Electric Company, the company is a research and development, production, sales, with "on the ancient" self-patent brands of solar water heater companies. I am responsible for the Inner Mongolia region, the development and maintenance of the market, with dealers and end users keep in close touch in time to understand and solve customers in the use of the problems and timely feedback to the head office in order to further promote the optimization and upgrading of products. Work in six months time, the development of Chifeng, Keqi, white, yellow, blue flag, a flag of the city of four of the five general agent, on sales of about 40,000 yuan. Customers well. The company has been recognized and praised the leadership!

In July 2007 to today, in the work of the Beijing State-ho billion company

Work experience in detail:

After graduation, the assessment interview, Hao billion into the capital Beijing, the company's main selling import Triangle, tooth-belt, with continuously variable, V-ribbed belts, round belts, and so on with the import of industrial-belt, (PVC, PU, PE ) Baseband chip nylon, Teflon imports of temperature-resistant fiber cloth, tape, glue machine belt, as well as network with a special belt of the processing, so gear from the same period, mechanical equipment, and so on. I am responsible for the development of the market in Beijing and services, started in March 2008 as director of the Beijing team, the original basis for the work, with Beijing's new team in charge of Beijing's belt, part of the process, at the same time responsible for the on-site in Beijing Services, including equipment selection and on-site belt joint services. More than 40 existing customers, including distributors involved, machinery, glass, can manufacturing, printing and packaging industries. The industry now have a set of ideas for their own sales and marketing ideas.

Self-evaluation

Honest and trustworthy, strong language and communication skills, organizational ability and willingness to work hard, really want to do the thing to do, and make a point to success! Like at work to learn and explore the sum and will help to absorb their own things, to improve and enhance their own.

Entry on

If I had the honor to become a member of your company to become a member, I will start my own understanding of the customers in resources, analysis of the region, dealers and end-user usage ratio, as a relatively large number of distributors, and end-users of the profits will be higher , After weighing the pros and cons, the focus of the telephone communication and further to visit.

In terms of price, I will use my hand, the same belt and Samsung, Obiang, such as Gates, compared to appropriate pricing, as much as possible to maximize profits.

Customers do in the process of fully understanding, and detailed records, as far as possible in the end-users, distributors and corporate conflict.

If you have the honor to be able to work in your company, I will do so before the combination of experience and a belt of your company's business philosophy, in the course of its work to improve their own professional standards, trying to find a more suitable for them, even more beneficial to the company's sales methods.

太长了