oracle 常用sql語句

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1）基本

2）數學函數

3）rownum

4）分頁

5）時間處理

6）字元函數

7）to_number

8）彙總函式

9）學生選課

10）圖書館借閱

 

基本

--建立表：create table table1( id varchar(300) primary key, name varchar(200) not null);--插入資料   insert into table1 (id,name) values (‘aa‘,‘bb‘); --更新資料   update table1 set id = ‘bb‘ where id=‘cc‘; --刪除資料   delete from table1 where id =‘cc‘; --刪除表    drop table table1; --修改表名： alter table table1 rename to table2; --表資料複製：insert into table1 (select * from table2); --複製表結構： create table table1 select * from table2 where 1>1; --複製表結構和資料：create table table1 select * from table2; --複製指定欄位： create table table1 as select id, name from table2 where 1>1;--條件查詢： select id,name (case gender when 0 then ‘男‘ when 1 then ‘女’ end  ) gender from  table1  

 

數學函數

--絕對值：abs()   select abs(-2) value from dual;          --(2)--取整函數（大）：ceil（）   select ceil(-2.001) value from dual;       --(-2)--取整函數（小）：floor（）   select floor(-2.001) value from dual;       --(-3)--取整函數（截取）：trunc（）   select trunc(-2.001) value from dual;       -- (-2)--四捨五入：round（）   select round(1.234564,4) value from dual;       --(1.2346)--取平方：Power（m,n）   select power(4,2) value from dual;       --(16)--取平方根:SQRT()   select sqrt(16) value from dual;       --(4)--取隨機數:dbms_random(minvalue,maxvalue)   select dbms_random.value() from dual;  (預設是0到1之間)　select dbms_random.value(2,4) value from dual;  （2-4之間隨機數）--取符號：Sign()　　select sign(-3) value from dual; --(-1)　　select sign(3) value from dual; --(1)--取集合的最大值:greatest(value)   select greatest(-1,3,5,7,9) value from dual;       --(9)--取集合的最小值:least(value)   select least(-1,3,5,7,9) value from dual;       --(-1)--處理Null值：nvl(空值，代替值)   select  nvl(null,10) value from dual;       --(10)　　   select nvl(score,10) score from student;

 

 

 rownum相關

--rownum小於某個數時可以直接作為查詢條件（注意oracle不支援select top）select * from student where rownum <3;--查詢rownum大於某個數值,需要使用子查詢，並且rownum需要有別名select * from(select rownum rn ,id,name from student) where rn>2;select * from (select rownum rn, student.* from student) where rn >3;--區間查詢select * from (select rownum rn, student.* from student) where rn >3 and rn<6;--排序+前n條select * from (select rownum rn, t.* from ( select d.* from DJDRUVER d order  by drivernumber)t )p where p.rn<10;--排序+區間查詢1select * from (select rownum rn, t.* from ( select d.* from DJDRIVER d order by DJDRIVER_DRIVERTIMES)t )p where p.rn<9 and p.rn>6;--排序+區間查詢2select * from (select rownum rn, t.* from ( select d.* from DJDRIVER d order by DJDRIVER_DRIVERTIMES)t where rownum<9 )p where p.rn>6;--效率遠高於方式一

 

 分頁查詢

（假設每頁顯示10條）

不包含排序：

--效率低select * from (select rownum rn, d.* from DJDRIVER d  )p where p.rn<=20 and p.rn>=10;
select * from (select rownum rn, d.* from DJDRIVER d  )p where p.rn between 10 and 20;--效率高 select * from (select rownum rn, d.* from DJDRIVER d where rownum<=20 )p where p.rn>=10;

包含排序：

--排序+區間查詢1（效率低）
select * from (select rownum rn, t.* from ( select d.* from DJDRIVER d order by DJDRIVER_DRIVERTIMES)t )p where p.rn<=20 and p.rn>=10;
select * from (select rownum rn, t.* from ( select d.* from DJDRIVER d order by DJDRIVER_DRIVERTIMES)t )p where p.rn between 10 and 20;--排序+區間查詢2（效率高） 
select * from (select rownum rn, t.* from ( select d.* from DJDRIVER d order by DJDRIVER_DRIVERTIMES)t where rownum<=20 )p where p.rn>=10;

 

 時間處理

1. to_char和to_date基本使用

--日期--年 yyyy yyy yy year--月 month mm mon month--日+星期  dd ddd(一年中第幾天) dy day --小時  hh hh24 --分 mi--秒 ss

eg1:

select to_char(sysdate,‘yyyy-mm-dd hh24:mi:ss‘)currenttime,        to_char(sysdate,‘yyyy‘) year,       to_char(sysdate,‘mm‘) month,       to_char(sysdate,‘dd‘) day,       to_char(sysdate,‘day‘) week,       to_char(sysdate,‘hh24‘)hour,       to_char(sysdate,‘mi‘) minute,       to_char(sysdate,‘ss‘) secondfrom dual;

eg2:

select to_date(‘2009-07-04 05:02:01‘,‘yyyy-mm-dd hh24:mi:ss‘)currenttime,       to_char(to_date(‘2009-07-04 05:02:01‘,‘yyyy-mm-dd hh24:mi:ss‘),‘yyyy‘)year,       to_char(to_date(‘2009-07-04 05:02:01‘,‘yyyy-mm-dd hh24:mi:ss‘),‘mm‘)month,       to_char(to_date(‘2009-07-04 05:02:01‘,‘yyyy-mm-dd hh24:mi:ss‘),‘dd‘) day,       to_char(to_date(‘2009-07-04 05:02:01‘,‘yyyy-mm-dd hh24:mi:ss‘),‘day‘) week,       to_char(to_date(‘2009-07-04 05:02:01‘,‘yyyy-mm-dd hh24:mi:ss‘),‘day‘,‘NLS_DATE_LANGUAGE=American‘) week, --設定語言       to_char(to_date(‘2009-07-04 05:02:01‘,‘yyyy-mm-dd hh24:mi:ss‘),‘hh24‘)hour,       to_char(to_date(‘2009-07-04 05:02:01‘,‘yyyy-mm-dd hh24:mi:ss‘),‘mi‘) minute,       to_char(to_date(‘2009-07-04 05:02:01‘,‘yyyy-mm-dd hh24:mi:ss‘),‘ss‘) secondfrom dual;

 

2）months_between

 select months_between(to_date(‘03-31-2014‘,‘MM-DD-YYYY‘),to_date(‘12-31-2013‘,‘MM-DD-YYYY‘)) "MONTHS" FROM DUAL;   

 

3)next_day

select sysdate today, next_day(sysdate,6) nextweek from dual;

 

4)時間區間

eg：

select cardid, borrowdate from borrow where to_date(borrowdate,‘yyyy-mm-dd hh24:mi:ss‘)  between to_date(‘2014-02-01 00:00:00‘,‘yyyy-mm-dd hh24:mi:ss‘) and to_date(‘2014-05-01 00:00:00‘,‘yyyy-mm-dd hh24:mi:ss‘); 

 

5）interval

select to_char(sysdate,‘yyyy-mm-dd hh24:mi:ss‘) currenttime,       to_char(sysdate - interval ‘7‘ year,‘yyyy-mm-dd hh24:mi:ss‘) intervalyear,          to_char(sysdate - interval ‘7‘ month,‘yyyy-mm-dd hh24:mi:ss‘) intervalMonth,          to_char(sysdate - interval ‘7‘ day,‘yyyy-mm-dd hh24:mi:ss‘) intervalday,          to_char(sysdate - interval ‘7‘ hour,‘yyyy-mm-dd hh24:mi:ss‘) intervalHour,          to_char(sysdate - interval ‘7‘ minute,‘yyyy-mm-dd hh24:mi:ss‘) intervalMinute,          to_char(sysdate - interval ‘7‘ second,‘yyyy-mm-dd hh24:mi:ss‘) intervalSecond    from dual; 

 

 

6）add_months

select add_months(sysdate,12) newtime from dual;

 

7)extract

 select extract(month from sysdate) "This Month",extract(year from add_months(sysdate,36)) " Years" from dual; 

 

 

字元函數

--字元函數select substr(‘abcdefg‘,1,5)substr,                     --字串截取       instr(‘abcdefg‘,‘bc‘) instr,                     --尋找子串              ‘Hello‘||‘World‘ concat,                         --串連              trim(‘  wish  ‘) trim,                           --去前後空格       rtrim(‘wish  ‘) rtrim,                           --去後面空格       ltrim(‘  wish‘) ltrim,                           --去前面空格              trim(leading ‘w‘ from ‘wish‘) deleteprefix,      --去首碼       trim(trailing ‘h‘ from ‘wish‘) deletetrailing,   --去尾碼       trim(‘w‘ from ‘wish‘) trim1,              ascii(‘A‘) A1,        ascii(‘a‘) A2,                                   --ascii(轉換為對應的十進位數)       chr(65) C1,        chr(97) C2,                                      --chr(十進位轉對應字元)              length(‘abcdefg‘) len,                           --length               lower(‘WISH‘)lower,        upper(‘wish‘)upper,        initcap(‘wish‘)initcap,                            --大小寫變換              replace(‘wish1‘,‘1‘,‘youhappy‘) replace,           --替換              translate(‘wish1‘,‘1‘,‘y‘)translate,               --轉換，對應一位(前面的位元大於等於後面的位元)       translate(‘wish1‘,‘sh1‘,‘hy‘)translate1,              concat(‘11‘,‘22‘) concat          　　　　　　　　   --串連

from dual;

 

 

 

to_number

--to_number(expr)--to_number(expr,format)--to_number(expr,format,‘nls-param‘)select to_number(‘0123‘)number1,            --converts a string to number       trunc(to_number(‘0123.123‘),2) number2,       to_number(‘120.11‘,‘999.99‘) number3,

 　　　 to_number(‘0a‘,‘xx‘) number4,        --converts a hex number to decimal       to_number(100000,‘xxxxxx‘) number5  from dual;

 

 

彙總函式

student表如下：

count：

--count (distinct|all)select count(1) as count from student;--效率最高select count(*) as count from student;    select count(distinct score) from student;     

語句1結果：11

 

avg

--avg (distinct|all)select avg(score) score from student;select avg(distinct score) from student;select classno,avg(score) score from student group by classno;

 

語句3輸出結果：

 

max

--max (distinct|all)select max(score) from student;select classno, max(score) score from student group by classno;

 

min

--min (distinct|all)select min(score) from student;select classno, min(score) score from student group by classno;

 

stddev（standard deviation）標準差

--stddevselect stddev(score) from student;select classno, stddev(score) score from student group by classno;

 

sum

--sumselect sum(score) from student;select classno, sum(score) score from student group by classno;

 

median--中位元

--medianselect median(score) from student;select classno, median(score) score from student group by classno;

 

 案例1--學生選課

1. 建立表 stu（學生表），course（課程表），選課表（s_c）

--建立表create table STU  (    id   NUMBER not null,    name VARCHAR2(255)  ) ;   create table COURSE  (    id  NUMBER not null,    coursename VARCHAR2(255)  ) ;    create table S_C  (    sid    NUMBER,    cid    NUMBER,    score NUMBER  );

 

2.插入資料

--插入資料Insert into STU (ID,NAME) values (1,‘wish‘);Insert into STU (ID,NAME) values (2,‘rain‘);Insert into STU (ID,NAME) values (3,‘july‘);Insert into STU (ID,NAME) values (4,‘joey‘);Insert into COURSE (ID,COURSENAME) values (1,‘math‘);Insert into COURSE (ID,COURSENAME) values (2,‘english‘);Insert into COURSE (ID,COURSENAME) values (3,‘Japanese‘);Insert into COURSE (ID,COURSENAME) values (4,‘chinese‘);Insert into S_C (SID,CID,SCORE) values (1,1,80);Insert into S_C (SID,CID,SCORE) values (1,2,90);Insert into S_C (SID,CID,SCORE) values (2,4,100);Insert into S_C (SID,CID,SCORE) values (4,4,90);Insert into S_C (SID,CID,SCORE) values (4,1,100);Insert into S_C (SID,CID,SCORE) values (4,3,80);Insert into S_C (SID,CID,SCORE) values (4,2,80);Insert into S_C (SID,CID,SCORE) values (2,1,90);Insert into S_C (SID,CID,SCORE) values (2,4,100);Insert into S_C (SID,CID,SCORE) values (3,1,60);

 

3.查詢學生選課情況

with vt as (select s.id,s.name,c.coursename,sc.score from stu s, course c, s_c sc where s.id=sc.sid and c.id=sc.cid)select * from vt order by id;

結果：

 

 

案例2--圖書館借閱

1.建立表： 圖書（book），讀者（reader），借閱（borrow）

--建立表 bookcreate table book(  bookId  varchar2(30),   --圖書總編號  sortid varchar2(30),    --分類號  bookname varchar2(100), --書名  author varchar2(30),    --作者  publisher varchar2(100),--出版單位  price number(6,2)       --價格  );  --建立表 reader  create table reader (  cardId varchar2(30),  --借書證號  org varchar2(100),    --單位  name varchar2(100),   --姓名  gender varchar2(2),   --性別  title varchar2(30),   --職稱  address varchar2(100) --地址);--建立表 borrowcreate table borrow(    cardId varchar2(30),  --借書證號  bookId  varchar2(30),   --圖書總編號  borrowDate varchar2(30) --借閱時間);

 

2.插入資料

--插入資料-bookinsert into book (bookId,sortid,bookname,author,publisher,price) values (‘aaa‘,‘a1‘,‘gone with the wind‘,‘CA‘,‘renmin‘,‘103‘);insert into book (bookId,sortid,bookname,author,publisher,price) values (‘bbb‘,‘a2‘,‘the little prince‘,‘CB‘,‘jixie‘,‘30‘);insert into book (bookId,sortid,bookname,author,publisher,price) values (‘ccc‘,‘a3‘,‘the ordinary world‘,‘CC‘,‘renmin‘,‘130‘);insert into book (bookId,sortid,bookname,author,publisher,price) values (‘ddd‘,‘a4‘,‘the little women‘,‘CA‘,‘dianzi‘,‘110‘);--插入資料-readerinsert into reader(cardid, org, name,gender, title, address)values (‘xxx‘,‘A‘,‘wish‘,‘1‘,‘student‘,‘bupt‘);insert into reader(cardid, org, name,gender, title, address)values (‘uuu‘,‘A‘,‘luna‘,‘1‘,‘student‘,‘bupt‘);insert into reader(cardid, org, name,gender, title, address)values (‘vvv‘,‘B‘,‘harry‘,‘1‘,‘student‘,‘bupt‘);insert into reader(cardid, org, name,gender, title, address)values (‘www‘,‘C‘,‘chander‘,‘2‘,‘professor‘,‘bupt‘);insert into reader(cardid, org, name,gender, title, address)values (‘yyy‘,‘A‘,‘joey‘,‘2‘,‘student‘,‘bupt‘);insert into reader(cardid, org, name,gender, title, address)values (‘zzz‘,‘B‘,‘richard‘,‘2‘,‘student‘,‘bupt‘);insert into reader(cardid, org, name,gender, title, address)values (‘OOO‘,‘A‘,‘micheal‘,‘2‘,‘student‘,‘bupt‘);insert into reader(cardid, org, name,gender, title, address)values (‘ppp‘,‘A‘,‘richal‘,‘2‘,‘student‘,‘bupt‘);insert into reader(cardid, org, name,gender, title, address)values (‘abp‘,‘A‘,‘michal‘,‘2‘,‘student‘,‘bupt‘);insert into reader(cardid, org, name,gender, title, address)values (‘ccp‘,‘A‘,‘mike‘,‘2‘,‘student‘,‘bupt‘);--插入資料-borrowinsert into borrow(cardid,bookid,borrowdate) values(‘xxx‘,‘aaa‘,‘2014-4-29‘);insert into borrow(cardid,bookid,borrowdate) values(‘xxx‘,‘bbb‘,‘2014-4-29‘);insert into borrow(cardid,bookid,borrowdate) values(‘xxx‘,‘ccc‘,‘2014-4-28‘);insert into borrow(cardid,bookid,borrowdate) values(‘yyy‘,‘ccc‘,‘2014-4-28‘);insert into borrow(cardid,bookid,borrowdate) values(‘yyy‘,‘ddd‘,‘2014-4-27‘);insert into borrow(cardid,bookid,borrowdate) values(‘yyy‘,‘aaa‘,‘2014-4-27‘);insert into borrow(cardid,bookid,borrowdate) values(‘zzz‘,‘bbb‘,‘2014-4-28‘);insert into borrow(cardid,bookid,borrowdate) values(‘zzz‘,‘ddd‘,‘2014-4-27‘);insert into borrow(cardid,bookid,borrowdate) values(‘zzz‘,‘aaa‘,‘2014-4-27‘);insert into borrow(cardid,bookid,borrowdate) values(‘uuu‘,‘bbb‘,‘2014-4-28‘);insert into borrow(cardid,bookid,borrowdate) values(‘uuu‘,‘ddd‘,‘2014-4-27‘);insert into borrow(cardid,bookid,borrowdate) values(‘uuu‘,‘aaa‘,‘2014-4-27‘);insert into borrow(cardid,bookid,borrowdate) values(‘uuu‘,‘ccc‘,‘2014-4-26‘);insert into borrow(cardid,bookid,borrowdate) values(‘vvv‘,‘bbb‘,‘2014-4-28‘);insert into borrow(cardid,bookid,borrowdate) values(‘vvv‘,‘ddd‘,‘2014-4-27‘);insert into borrow(cardid,bookid,borrowdate) values(‘www‘,‘aaa‘,‘2014-4-27‘);insert into borrow(cardid,bookid,borrowdate) values(‘www‘,‘ccc‘,‘2014-4-26‘);

表資訊如下：

book------> reader-------> borrow

 

 

3. 查詢A單位借閱圖書的讀者人數和人員詳細資料

人數：

with vt1 as (select cardid from reader where reader.org=‘A‘)select count(1) from vt1 where exists (select cardid from borrow where borrow.cardid=vt1.cardid);

詳細資料：

with vt1 as (select cardid,name,org from reader where reader.org=‘A‘)select cardid,name,org from vt1 where exists (select cardid from borrow where borrow.cardid=vt1.cardid);

 

4.查詢借書證號尾字元為‘p‘的讀者

select cardid, name, org from reader where cardid like ‘%p‘;

 

5. 查詢名字以m開頭的女性讀者，‘1’顯示為女，‘2’顯示為男

select cardid, name, org, case when gender=‘1‘ then ‘女‘ when gender=‘2‘ then ‘男‘ else ‘其他‘ end genderfrom reader where name like ‘m%‘;

 

6. 2014年2-4月借過書的讀者

1)查詢滿足條件的讀者（僅包含cardid）--未去重

　　方式一：

select cardid, borrowdate from borrow where to_char(to_date(borrowdate,‘yyyy-mm-dd‘),‘yyyy‘)=‘2014‘ and to_char(to_date(borrowdate,‘yyyy-mm-dd‘),‘mm‘)>=‘02‘and to_char(to_date(borrowdate,‘yyyy-mm-dd‘),‘mm‘)<=‘04‘;

　　方式二：

select cardid, borrowdate from borrow where to_char(to_date(borrowdate,‘yyyy-mm-dd‘),‘yyyy‘)=‘2014‘  --查詢and to_char(to_date(borrowdate,‘yyyy-mm-dd‘),‘yyyy-mm‘)>=‘2014-02‘and to_char(to_date(borrowdate,‘yyyy-mm-dd‘),‘yyyy-mm‘)<=‘2014-04‘;

　　方式三：

select cardid, borrowdate from borrow where to_date(borrowdate,‘yyyy-mm-dd hh24:mi:ss‘)  between to_date(‘2014-02-01 00:00:00‘,‘yyyy-mm-dd hh24:mi:ss‘) and to_date(‘2014-05-01 00:00:00‘,‘yyyy-mm-dd hh24:mi:ss‘); 

 

2) 查詢+去重

select distinct cardid from borrow where to_char(to_date(borrowdate,‘yyyy-mm-dd‘),‘yyyy‘)=‘2014‘  --查詢+去重and to_char(to_date(borrowdate,‘yyyy-mm-dd‘),‘yyyy-mm‘)>=‘2014-02‘and to_char(to_date(borrowdate,‘yyyy-mm-dd‘),‘yyyy-mm‘)<=‘2014-04‘;

select distinct cardid from borrow where to_date(borrowdate,‘yyyy-mm-dd hh24:mi:ss‘)  between to_date(‘2014-02-01 00:00:00‘,‘yyyy-mm-dd hh24:mi:ss‘) and to_date(‘2014-05-01 00:00:00‘,‘yyyy-mm-dd hh24:mi:ss‘); 

 

3）查詢+去重+讀者姓名等資訊

with vt1 as (select distinct cardid from borrow where to_char(to_date(borrowdate,‘yyyy-mm-dd‘),‘yyyy‘)=‘2014‘ and to_char(to_date(borrowdate,‘yyyy-mm-dd‘),‘yyyy-mm‘)>=‘2014-02‘and to_char(to_date(borrowdate,‘yyyy-mm-dd‘),‘yyyy-mm‘)<=‘2014-04‘)select cardid, name,org from reader where exists (select cardid from vt1 where vt1.cardid=reader.cardid);

轉自：http://www.cnblogs.com/wishyouhappy/p/3700683.html

oracle 常用sql語句