1. as的使用方法
as...as 的用法
as...as 意为"和……一样"，表示同级的比较。使用时要注意第一个 as 为副词，第二个 as为连词。其基本结构为：as+ adj./ adv. +as。例如：
(1)This story is as funny as that one.
这个故事和那个一样滑稽可笑。
(2)His bike rides as well as hers.
他的自行车和她的一样好骑。
其否定式为 not as/so +adj./ adv. +as。例如：
This book is not so/as necessary as they say.
这本书不想他们说的那么必不可少。
若有修饰成分，如 twice, three times, half, a quarter 等，则须置于第一个 as 之前。例如：
Your car is twice as big as mine.
你的车是我的两倍大。
几个关于 as...as 的常见句型：
(1)as...as possible
They ran away as quickly as they could.
请尽快回答我的问题。
(2)as...as usual/before
He looks as handsome as before.
他看起来和以前一样英俊。
(3)as long as... (引导条件状语从句)
It took us as long as three years to carry out the plan.
我们花了长达三年的时间才完成这项计划。
(4) as far as
We walked as far as 2 kilometres yesterday.
昨天，我们三步两公里远。
(5) as well as
He paints as well as his father does.
他画的画和他父亲一样好。
一些带有 as...as 结构的常见短语归纳：
as busy as a bee 像蜜蜂一样忙碌
as easy as ABC 像 ABC 一样容易
as deep as a well 像井一样深
as light as a feather 像羽毛一样轻
as soft as butter 像黄油一样软
as rich as a Jew 像犹太人一样富裕
常见的还有：
as green as grass 碧绿如青草
as big as an elephant 大如象
as small as a pea 小似豆
as red as an apple 红如苹果
as happy as a bird 开心得像只小鸟
as white as snow 雪白
as black as a mouse 黑似老鼠
as quiet as a sheep 腼腆如小羊
一、“as(否定句中可用 so)＋adj．／adv．＋as…”，其基本意思为“……和……一样”。但在实际应用中，此结构在不同的语境中含义差异较大。
1、表示不同人或物同一性质的比较，意为“……和……一样……"。
The wall is as white as snow．
这墙面雪白雪白的。
Mike is as intellent as Ben．
迈克与本一样机智。
2、表示同一个人或物不同性质的比较，意为“既……又……”
Karen talks as happily as she dances．
凯润愉快交谈，尽情跳舞。
Frank is not so wise as he is witty．
弗兰克为人风趣，但欠明智。
3、用于表示两个人或物不同性质的比较，表示程度相同或相当，意为“……而……”。
He was as handsome as his wife was beautiful．
他长得非常英俊，他的妻子也长得非常漂亮。
He was as experienced as his brother was green．
他经验丰富，而他兄弟却涉世未深。
二、as…as 结构的另一种形式是“as much／many＋名词＋as＋从句”。
Martin has painted as many pictures as his hather．
马丁已经画了和他爸爸一样多的画。
It is as much your fault as your his．
这既是你的过错，也是他的过错。
Henry is as much a hero as John．
亨利跟约翰一样是个英雄。
三、若有修饰成分，如 twice，three times，half，a quaer 等，必须置于第一个 as 之前。
You are not half as wise as you think．
你可不像自己想象的那么智慧。
She will never go out with a man who is twice as old as she．
她永远不会和一个比她大一倍的人出去散步。
He's made just as many mistakes as I have．
他和我犯的错误一样多。
We’ve produced twice as much cotton this year as we did last year.
我们今年的棉花产量是去年的两倍。
四、as…as 结构的另一变体形式是“as＋形容词原级＋名词词组＋as”
I don't want as expensive a car as this.
＝I don't want a car as expensive as this．
我不要这么贵的汽车。
Tony is as clever a boy as his brother．
托尼是一个和他兄弟一样聪明的男孩。
五、当 as…as 与表示重量、数量、时间、距离、价格等的计量名词连用时。往往并不表示比较。而是构成一个形容词组，意为“重达……，多达……，高达……”等。
The river is as deep aslO meters．
这条河深达 10 米。
Frosts often occur as late as May．
往往到 5 月份还有霜。
六、“as+原级+asany(或 ever)”、“as+原级+as…canbe”、“nothing(或 no)＋so＋原级＋as…”等结构表达的是最高级意义。即在某种程度上或某方面达到极限或最大限度。
He is as great a mathematician as any．
他是一位非常杰出的数学家。
He is as happy as happy can be．
他幸福无比。
No one is so deaf as those who won’t listen．
最聋者莫过于不听劝说的人。
七、as…as…不表示比较的几个常见句型。
1．as…as possible／sb can 尽 可 能 的 ……
Please answer my question as soon as possible．
请尽快回答我的问题。
The detective is searching the man as carefully as he can．
那个侦探正在尽可能仔细地搜查那个男子的身体。
2．as…as usual／before 像以前一样……
She looks as pretty as before．
她看起来和以前一样漂亮
Though they failed，they still worked as hard as usual．
尽管他们失败了，但他们仍像以前一样努力工作。
3．as long as 只要，引导条件状语从句
Ｉ will stay with you as long as there is a room flree．
要是你有一间空余的房子，我就住在你这里。
You may borrow this book as long as you promise to give itback．
只要你答应归还，你就可以把这书借走。
一、as 作连词的用法
1. as...as 的用法
as...as 意为"和……一样"，表示同级的比较。使用时要注意第一个 as 为副词，第二个 as 为连词。其基本结构为：as+ adj./ adv. +as。例如：
(1) This film is as interesting as that one.
这部电影和那部电影一样有趣。
(2) Your pen writes as smoothly as mine.
你的钢笔书写起来和我的一样流畅。
其否定式为 not as/so +adj./ adv. +as。例如：
This dictionary is not as/so useful as you think.
这本字典不如你想象的那样有用。
若有修饰成分，如 twice, three times, half, a quarter 等，则须置于第一个 as 之前。例如：
Your bag is twice as expensive as mine.
你的袋子比我的贵一倍。几个关于 as...as 的常见句型：
(1) as...as possible
Please answer my question as soon as possible.
请尽快回答我的问题。
(2) as...as usual/before
She looks as pretty as before.
她看起来和以前一样漂亮。
(3)as long as... (引导条件状语从句)
It took us as long as three years to carry out the plan.
我们花了长达三年的时间才完成这项计划。
(4) as far as
He walked as far as the railway station yesterday evening.
昨天傍晚，他一直散步到火车站。
(5) as well as
She cooks as well as her mother does.
她烧菜烧得跟她母亲一样好。一些带有 as...as 结构的常见短语归纳：
as busy as a bee 像蜜蜂一样忙碌
as easy as ABC 像 ABC 一样容易
as deep as a well 像井一样深
as light as a feather 像羽毛一样轻
as soft as butter 像黄油一样软
as rich as a Jew 像犹太人一样富裕
2. as 用作连词引导时间状语从句
as 与 when，while 都是引导时间状语从句的从属连词，含义都是"当…… 的时候"。但它们有区别：
用 when 时，从句的动作可以与主句的动作同时发生， 也可以先于主句的动作发生；
用 while 时，从句的动作为一过程，主句动作与从句动作同时进行或在从句动作过程中发生；
用 as 时，主句和从句的动作同时发生，具有延续的含义。例如：
(1) It was snowing when he arrived at the construction site.
他到达工地时，天正在下雪。
(2) He was watching TV while his mother was cooking.
他母亲做饭时他在看电视。
(3) You will grow wiser as you grow older.
你会随着年龄的增长而越来越聪明。
3. as 用作连词引导原因状语从句
as，because，since 都可以表示因果关系，连接原因状语从句，含义是" 因为，由于"，但它们有区别：because 表示的语气最强；as 一般放在句首，语气较弱，较口语化；since 常常用在书面语中，表示多为对方已知的、或稍加分析便可得知的原因，有时可译作"既然"。例如：
(1) He will succeed because he is in earnest.
他一定会成功，因为他很认真。
(2) Since you are so sure of it he”ll believe you.
既然你对此如此有把握，他会相信你的。
(3) As rain has fallen, the air is cooler.
因为下过雨，空气比较清爽。
4. as 作连词引导让步状语从句
as 与 although (或 though)，however (或 no matter how)等都可以引导让步状语从句，但有所不同：
although 语气稍正式些，主句中不能再用 but，但可以用 yet；
as 所表示的语气较强，引导的让步状语从句用倒装语序；
however 引导让步状语从句时， 它的后面可跟形容词或副词，也要用倒装语序。例如：
(1)Although he is rather old, he still takes a long walk every day.
尽管他已经是上了春秋的人，他依然每天散步很长时间。
(2) Strange as it may seem, nobody was injured in the accident.
这个事故虽然看上去怪怪的，可是却没有人受伤。
(3) However hard I have tried, I still can't achieve my dream.
无论我如何尝试，都无法实现我的梦想。
二、as 作关系代词的用法
关系代词 as 引导定语从句时，其用法要比 that 和 which 复杂。
1. as 引导定语从句的搭配
①用于 the same...as 结构中
This is the same book as you bought.
这本书和你买的一样。
②用于 such...as 结构中
I don't like such books as he suggests.
我不喜欢他建议的那些书。
③用于"so +adj. + a/an + n. (单数) + as "结构中
I am not so active as I was.
我不像以前那么精力充沛了。
2. as 单独引导定语从句
as 单独引导定语从句时，先行词可以是一个词，也可以是一个句子或短语。例如：
(1) He is late again, as is often the case.
他又迟到了，这是家常便饭。(as指代前面整句话)
(2) To shut your eyes to facts, as many of you do, is foolish.
对事实视而不见--你们好多人都是如此的愚蠢。(as指代前面的不定时短语)
三、as 当介词用
as 作介词，意思是"作为"，"以……身份"。例如：
He works as an English in our school.
他以英语老师的身份在我们学校工作。
四、as 作副词的用法
意思接近to the same degree or amount; equally "相同地"，"同样地"。例如：
We don't have as much as money.
我们没有同样多的钱
2. as 怎么用
1、对表或者字段起别名, 用到as
2、创建触发器 过程 函数 用到as(is 可以代替) create or replace trigger/procedure/function
3、创建视图 create view view_name as select 这里只能用as
as一般用在两个地方, 一个是query的时候, 用来重新制定返回的column(字段)名字, 比如: 一个table有一个column叫id, 我们的query是select id from table1, 但是如果你不想叫id了, 就可以重新命名, 如叫systemID 就可以这样写 select id as systemID from table1
还有一个用法就是在creat table (创建表的时候)或者procedure的时候, as是个关键字例如:create table test as select * from table1，这时候就会创建一个table test, 他会完全copy table1 的全部数据
sql 建立存储过程的时候，create procdure name as (is) begin end ;建立procedure 这个时候as和is 可以互换。
扩展资料
标准SQL语句
虽然关系型数据库有很多，但是大多数都遵循SQL（结构化查询语言，Structured Query Language）标准。 常见的操作有查询，新增，更新，删除，求和，排序等。
查询语句：SELECT param FROM table WHERE condition 该语句可以理解为从 table 中查询出满足 condition 条件的字段 param。
新增语句：INSERT INTO table （param1，param2，param3） VALUES （value1，value2，value3） 该语句可以理解为向table中的param1，param2，param3字段中分别插入value1，value2，value3。
更新语句：UPDATE table SET param=new_value WHERE condition 该语句可以理解为将满足condition条件的字段param更新为 new_value 值。
删除语句：DELETE FROM table WHERE condition 该语句可以理解为将满足condition条件的数据全部删除。
去重查询：SELECT DISTINCT param FROM table WHERE condition 该语句可以理解为从表table中查询出满足条件condition的字段param，但是param中重复的值只能出现一次。
排序查询：SELECT param FROM table WHERE condition ORDER BY param1该语句可以理解为从表table 中查询出满足condition条件的param，并且要按照param1升序的顺序进行排序。
3. as用法详解
as in
意思：如; 例如; 为; 在; 是。用法参考如下例句：
[例句]The words of this report are as apt today as in 1929.
这份报告的措词用在今天和用在1929年一样贴切。
Sara wished Franklin to follow family tradition, in this as in all things.
萨拉希望富兰克林在这件事上和所有其他事情一样，能遵循家庭传统。
Buying the best is as sure a route to success in investment as in any other field.
和其他领域一样，投资领域获得成功的途径也是买进最佳商品。
As in all experimental sciences, we still do not know everything about nutrition.
就像所有实验科学一样，我们仍然没有完全认识营养作用。
You should have seen his roses! As good a show as in the Botanic Garden.
你真该看看他种的玫瑰！就跟植物园里的一样绚丽迷人。
The public square is as brightly lit as in daylight.
广场上灯火辉煌，如同白昼。
4. 关于as as的用法
as的意思：当……时，因为
as...as：与……一样
5. as使用教程
as 作为连词,其意义和用法主要有：
①（ 意为“当……之时”,引导时间状语从句,在意思上相当于 when 和 while 引导的时间状语从句.
例如：
As he grew up, he became silent. （他长大以后,变得沉默寡言
② 意为“作为……（某种身份）,当做,视为”.
例如：
As a student, you must obey the rules. （作为学生,你必须遵守纪律.
as引导时间状语从句多用于口语，强调“同一时间”或“一先一后”，有时还有“随着”的含义。
例1：As I was going out, it began to rain.
当我出门时，开始下雨了。(as强调两个动作紧接着发生，不强调下雨的特定时间。)
例2：As time goes on, he will understand what I said.
随着时间的推移，他会理解我所讲的'话。
as引导原因状语从句：
as表示“因为”，与because相比，较口语化，所表达的原因语气较弱，所表的原因比较明显，或是已知的事实。
例1：As the weather is so bad, we have to delay our journey.
因为天气太糟糕，我们不得不推迟旅行
6. as的使用方法翻译成英语
as +形容词或副词+as表示"和…一样"，例如：
Their library is as large as our library/ours.他们的图书馆和我们的一样大。
He speaks English as well as an American.他英语说得和美国人一样好。
7. as一般怎么用
The tree is as tall as the building (is) 中第一个 as 是副词，修饰形容词 tall ；第二个 as 是连词，引导 比较状语从句，从句中的谓语动词往往会省略。
谓语动词省略后，as 接近介词的用法。
例如 He is as tall as I am，口语中一般用 He is as tall as me。
8. as怎么使用
1、as用作副词时主要用来表示比较，意思是“像…一样；如同”。可以单独使用，但更多的是用在as...as结构中，其中第一个as是副词，其后可接形容词或副词，也可接其他成分，as前可有状语。第二个as可以是介词，也可以是连词。
2、as...as结构多用于肯定式，偶尔也可用于否定式。表示同样意思的否定式多用so...as。as...as结构用于否定句时多用于口语，侧重“像…一样”；so...as结构则多用于书面语，侧重“像…那样”。
3、as...as结构表示的是同级比较，第一个as后的形容词或副词不可用比较级，必须用原级，比较的对象亦须属同类。
9. as as怎么用
一、指代不同
1、as to：至于。
2、as for：关于。
二、侧重点不同
1、as to：as to 常常与 wh-疑问词引导的动词不定式和名词从句连用（有时可省略），而 as for 却没有此种用法。
2、as for：as for 在语体上不如 as to 正式，并且着重话题的转换，也就是说，它所引导的是前面尚未提到过的新的事情，因此，它不能用于文章的开头。
三、引证用法不同
1、as to：as用作副词时主要用来表示比较，意思是“像…一样；如同”。可以单独使用，但更多的是用在as...as结构中，其中第一个as是副词，其后可接形容词或副词，也可接其他成分，as前可有状语。
2、as for：as用作连词时，可以用来表示时间，译为“正当…的时候;随着…;边…边…”，引导时间状语从句。主句可以是主动句，也可以是被动句。
