SELECT 列名1，列名2... INTO 变量1，变量2... FROM 表名WHERE 条件；注意：接收查询结果的变量类型、顺序和个数同SELECT语句的字段的类型、顺序和个数应该完全一致。并且SELECT语句返回的数据必须是一行，否则将引发系统错误。当程序要接收返回的多行结果时，可以采用后面介绍的游标的方法。
Unit13虚拟语气专题讲解 【知识要点】 语气（mood）是一种动词形式，用以表示说话者的意图或态度。 英语有三种语气： ＊直陈语气（indicative mood）---- 事实 France lies to the east of England. ＊祈使语气（imperative mood）---- 请求、命令 Make yourself at home. ＊虚拟语气（subjunctive mood） If there were no air and water , we should not be able to live on the earth. 虚拟语气表示说话人的一种主观愿望或假想，所说的是一个条件而不一定是事实，或与事实相反。 一. 虚拟语气在if条件状语从句中的用法 假设类型条件从句谓语 动词形式 主语谓语 动词形式 与现在事实相反动词的过去式(be用were而不用was) should/ would /could/ might+动词原形 与过去事实相反had + 过去分词 should/ would/could /might + have+过去分词 与将来事实相反1.should+动词原形 2.动词过去式 3.were to+动词原形 should/ would/ could/ might +动词原形 1. 在错综条件句子中，虚拟条件从句和主句动作发生的时间不一致，因此，主句和从句的谓语动词应根据所指的时间选用适当的虚拟语气形式。 1）If I were you，I wouldn't have missed the film last night． 2）If he had followed the doctor's advice，he would recover already．（从句与过去事实相反，主句与现在事实相反。） 2、在if虚拟条件句中，有时可把连词省去，采用倒装语序把谓语动词were或助动词did，had，should 移到句 首构成非真实条件从句的另一种句型，其意思不变。 1）Had we time to spare，we would be glad to go to the park． 2）Were it not for the discovery of electricity，the modern world would experience great inconvenience． 3、有时假设的情况不用if引导虚拟条件从句来表述，而用介词（如without， but for等）引出的短语、分词 （如supposing等）引出的短语、并列连词（如or，otherwise，but，though等）、由动词suppose引出的祈使句或通过上下文的意思来表达。此时句中谓语动词仍采用虚拟语气的相应形式。 1）But for your advice，I would not be able to do this work． 2）Victor obviously doesn't know what's happened，otherwise he wouldn't have made such a stupid remark．。
表格基本语法
表格(TABLE)标记(TAGS) 表格的基本语法
...
- 定义表格
- 定义表行
- 定义表头
- 定义表元(表格的具体数据) 带边框的表格：
Food
Drink
Sweet
A
B
C
不带边框的表格：
Food
Drink
Sweet
A
B
C
Food Drink Sweet A B C 跨多行、多列的表元(Table Span) 跨多列的表元
2012届高考英语二轮专题总复习语法部分虚拟语气 表示说话人所说的话不是事实，而是一种假设、愿望、怀疑或推测。 虚拟语气在if条件从句中的使用 【观察】 If I were you, I would go to bed early tonight. 如果我是你，我今晚就会早点睡。If you took the bus, you would be late for the film. 如果你坐公车去看电影，那么你就会迟到。 If Jack had scored that goal, we would have won the football match. 如果杰克射进了那个球，我们就会赢得那场足球比赛。 If she hadn’t come, I might have been in trouble. 如果她没来，我可能已陷入困境了。 I could help you if you had difficulty in doing your homework. 如果你做作业有困难，我会帮助你的。 If it were to rain tomorrow, they would not go out. 如果明天下雨的话，他们就不会出去。 【归纳】 注意：若从句中的谓语动词是be动词的话，一律用were。 【实践】 1.If he my advice, he wouldn’t have lost his job. A. followed B. should follow C. had followed D. would follow 2. 翻译：如果我有足够的钱，我会周游世界。 If I had enough money, I would travel around the world. 翻译：如果明天见到他，我会邀请他到我家。 If I should see / were to see / saw him tomorrow, I would invite him to my house. 虚拟语气用于条件状语从句时，可以转换成下列形式： （1）省略if, 用“were, had, should + 主语”。如： Were she my daughter, I wouldn’t allow her to study abroad. 如果她是我女儿，我就不让她出国学习了。 Had I worked hard, I would have surely succeeded. 如果我当时努力学习的话，我肯定会成功的。 Should there be a meeting tomorrow, I would come. 如果明天有会议，我会来。 （2）含蓄条件句。虚拟语气句中不出现if 条件句，而是用介词、介词短语或连词通过上下文表现出来，这时须根据句子的含义判定是用虚拟现在式还是虚拟过去式。常见短语有：but for, without, otherwise, or 等。如：
高中英语语法-虚拟语气全总结
虚拟语气在非真实条件句中
①错综时间条件句: 当条件状语从句表示的行为和主句表示的行为所发生的时间不一致时，被称为错综时间条件句，动词的形式要根据它表示的时间作出相应的调整。如： If you had followed my advice just now, you would be better now. If you had studied hard before, you would be a college student now. ②if省略句 在条件句中可以省略if, 把were, had, should提到句首，变成倒装句式。如：If I were at school again, I would study harder. →Were I at school again, I would study harder. 如果我还有上学的机会，我会更加努力学习。 If you had come earlier, you would catch the bus. →Had you come earlier, you would catch the bus. 如果你来得早点，你就能赶上公共汽车。 If it should rain tomorrow, we would not go climbing. →Should it rain tomorrow, we would not go climbing. 如果明天下雨的话，我们就不能登山去了。 ③用介词代替条件状语从句 常用的介词有with, without, but for。如： What would you do with a million dollars? (=if you had a million dollars) 如果你有100万元，你会做什么？ We couldn?t have finished the work ahead of time without your help. (=if we
ORACLE 11g SELECT 语句基础语法
一、SELECT语句基础语法 SELECT [ALL |DISTINCT TOP N [PERCENT] WITH TIES SELECT_LIST #SELECT 子句，用于指定由查询返回的列。 [INTO [new_table_name]] #INTO子句，将检索结果存储到新表或视图中。 FROM {table_name|view_name} [(optimizer_hints)],... #FROM子句，用于指定引用的表或视图，需指定多个表或视图，用“，”分开即可。[WHERE search_condition] #WHERE子句，用于指定限制返回的行的搜索条件，若无此子句，则默认表中的所有行都满足条件。 [GROUP BY group_by_expression] #GROUP BY子句，指定用来放置输出行的组，并且如果SELECT子句中
情态动词和虚拟语气 1. (2016 北京,29)—Can't you stay a little longer 一It's getting late. I really_________go now. My daughter is home alone. 2. (2016 北京，34)If I_________(see) it with my own eyes,I wouldn't have believed it. 3. (2016 福建，27)—Sorry, Mum! I failed the job interview again. —Oh, it's too bad. You _________ have made full preparations. 4. (2016 安徽，32) It is lucky we booked a room, or we _________(have) nowhere to stay now. 5. (2016 四川，2)You_________be careful with the camera. It costs! 6. (2016 陕西，23)Ellen is a fantastic dancer. I wish I_________ (dance) as well as her. 7. (2016 天津)_________have worried before I came to the new school, for my classmates here are very friendly to me. 8. (2016 天1 wish I _________(be) at my sister's wedding last Tuesday, but I was on a business trip in New York then. 9. (2016 重庆，12) You _________ be Carol. You haven't changed a bit after all these years. 10. (2015湖南，25)—I’ve prepared all kinds of food for the picnic. —Do you mean we_________not bring anything with us 11. (2015福建，32)_________(be) there no modem telecommunications, we would have to wait for weeks to get news from around the world. 12. (2015陕西）We would rather our daughter_________(stay) at home with us, but it is her choice, and she is not a child any longer. 13. (2015重庆，3) I，we ordered some pizza, so we _________ worry about cooking when we get home tired. 14. (2015重庆，13)It was John who broke the window. Why are you talking to me as if I_________(do) it 15 (2015陕西，25)My book, The House of Hades,is missing. Who_________ have taken it 16. (2015四川，6)I still remember my happy childhood when my mother _________ (will) take me to Disneyland at weekends. 17 (2015湖南) If Mr Dewey_________(be) present, he would have offered any possible assistance to the people there. 18 (2014 天津，9)No one_________be more generous; he has a heart of gold. 19. (2014 浙江，3)1_________(not enjoy) myself more—it was a perfect day. 20 (2014 天津，14) If he had spent more time practicing speaking English before, he_________(be) able to speak it much better now. 21. (2014 陕西，12)My mom suggests that we_________(eat) out for a change this weekend. 22. (2014 辽宁，31) Harry is feeling uncomfortable. He _________(drink) too much at the party last night. 23. (2014 新课标Ⅰ，29) The door_________ not open, no matter how hard she pushed. 15. (2014 重庆，29)—It rained cats and dogs this morning. I'm glad we took an umbrella. —Yeah, we would have got wet all over if we _________(have).
--创建用户 create user han identified by han default tablespace users Temporary TABLESPACE Temp; grant connect,resource,dba to han; //授予用户han开发人员的权利 --------------------对表的操作-------------------------- 创建表格语法: create table 表名( 字段名1 字段类型(长度) 是否为空, 字段名2 字段类型是否为空 ); -增加主键 alter table 表名 add constraint 主键名 primary key (字段名1); -增加外键: alter table 表名 add constraint 外键名 foreign key (字段名1) references 关联表 (字段名2); 在建立表格时就指定主键和外键 create table T_STU ( STU_ID char(5) not null, STU_NAME varchar2(8) not null, constraint PK_T_STU primary key (STU_ID) ); 主键和外键一起建立： create table T_SCORE ( EXAM_SCORE number(5,2), EXAM_DATE date, AUTOID number(10) not null, STU_ID char(5),
SUB_ID char(3), constraint PK_T_SCORE primary key (AUTOID), constraint FK_T_SCORE_REFE foreign key (STU_ID) references T_STU (STU_ID) ) --创建表 create table classes( id number(9) not null primary key, classname varchar2(40) not null ) --查询表 select * from classes; --删除表 drop table students; --修改表的名称 rename alist_table_copy to alist_table; --显示表结构 describe test --不对没查到 -----------------------对字段的操作 ----------------------------------- --增加列 alter table test add address varchar2(40); --删除列 alter table test drop column address; --修改列的名称 alter table test modify address addresses varchar(40; --修改列的属性 alter table test modi create table test1( id number(9) primary key not null, name varchar2(34)
英语语法专项：虚拟语气用法详解及练习(附答案)
虚拟语气用法详解 一、条件句中的虚拟语气 1. 条件句中虚拟语气的形式 从句中提出一种与客观现实不相符或根本不可能存在的条件，主句会产生的一种不可能获得的结果。条件句中 的虚拟语气根据不同的时间有三种不同的形式。 2. 条件句中的虚拟语气的举例 (1) 将来时的条件句中的虚拟语气。如： If he should go to Qing Hua University, he would make full use of his time. 如果他要上清华大学的话，他就会充分 利用他的时间了。 If he were to come here, he would tell us about it. 如果他要来的话，他会通知我们一声。 (2) 现在时的条件句中的虚拟语气。如： If he were free, he would help us. 要是他有空的话，它会帮助我们的。 If he studied at this school, he would know you well. 如果他在这所学校学习的话，它会对你很熟悉。 (3) 过去时的条件句中的虚拟语气。如： If I had seen the film, I would have told you about it. 我如果看过这场电影，我会把电影内容告诉你了。 If I had got there earlier, I would have met Mr. Li. 如果我早点到那儿，我就会会到了李先生。 3. 运用条件句中的虚拟语气时，须注意的几个问题 (1) 当从句的主语为第三人称单数时，谓语动词若是系动词be 时，可用was 代替were。但在倒装虚拟结构及if I were you, as it were 中，只能用were。如： Were I ten years younger, I would study abroad. 要是我还年轻十岁的话，我会去国外学习。 If I were you, I would try my best to grasp the chance. 要是我是你的话，我要尽力抓住这次机会。 (2) 有时，虚拟条件句中，主、从句的动作若不是同时发生时，须区别对待。①从句的动作与过去事实相反，而主句的动 作与现在或现在正在发生的事实不符。如： If I had worked hard at school, I would be an engineer, too. 如果我在学校学习刻苦的话，我现在也会使工程师了 If they had informed us, we would not come here now. 如果他们通知过我们的话，我们现在就不会来这里了。
oracle语法大全
第一篇基本操作 --解锁用户alter user 用户account unlock; --锁定用户alter user 用户account lock; alter user scott account unlock; --创建一个用户yc 密码为a create user 用户名identified by 密码； create user yc identified by a; --登录不成功，会缺少create session 权限，赋予权限的语法grant 权限名to 用户；grant create session to yc; --修改密码alter user 用户名identified by 新密码； alter user yc identified by b; --删除用户 drop user yc ; --查询表空间 select *from dba_tablespaces; --查询用户信息 select *from dba_users; --创建表空间 create tablespace ycspace datafile 'E:\oracle\app\product\11.2.0\dbhome_1\oradata\ycspace.dbf' size 2m autoextend on next 2m maxsize 5m offline ; --创建临时表空间 create temporary yctempspace tempfile 'E:\oracle\app\product\11.2.0\dbhome_1\oradata\ycspace.dbf' size 2m autoextend on next 2m maxsize 5m offline ; --查询数据文件 select *from dba_data_files;
高中英语语法专题虚拟语气练习(附答案)
虚拟语气 一、用所给动词的正确形式填空，注意使用合适的情态动词助动词 1. If I _____ my teacher before I graduated, I _____ him how much I appreciated him.(see, tell) 2. What do you think would happen if there_____no water in the world?(be) 3. But for the help from the police, I couldn’t_____ the hospital as soon as possible.(find) 4. It was demanded that no smoking _____ in the office, which made me satisfied. (allow) 5. If there had not been the new roads built by him, no changes _____ place in this small village. (take) 6. If Mr Wang _____ late for the meeting this weekend, what should we do? (come) 7. The hard study requires that I _____ at 5 o’clock every morning.(get up) 8. I wish I _____ the film the day before yesterday.(see) 9. It is natural that our government _____ the plan they had made.(stick) 10. How I wish every family______a warm house in such cold weather.(have) 二．单选 1. If you had given me enough time, I___ my part of the work. A. would finish B. must have finished C. would have finished D. had finished 2. Five minutes earlier, we ___ the train. A. will catch B. would catch C. would have caught D. will have caught 3. Our English teacher requires that we ___ a essay everyday. A. write B. written C. would write D. will write 4.Had my sister studied hard this term, she___ the final exam with flying colours. A. would pass B. could pass C. had passed D. would have passed 5.I wish I ___ what is happening there in WuHan now. A. know B. known C. knew D. should know 6.It is important that we ___ sports every day in the room because of the coronavirus. A. have B. would have C. must have D. will have 7.If there were no clear air in the world, everything including you and me ___. A. will die B. would die C. would have died D. would have been dead 8. ___ what was going to happen, I would never have left for America. A. Had I known B. If I know C. If I knew D. If had I known 9.The goverment ordered that the rescue operation ___ right away. A. should start B. started C. would be started D. be started 10. If only I _____ my new iphone!
