oracle 常用语法整理

 1 CREATE OR REPLACE PROCEDURE proc_testfor
 2 AS 
 3 V_empno NUMBER;
 4 BEGIN
 5 FOR curr_row IN 
 6 (
 7 SELECT * FROM EMP a LEFT JOIN DEPT ON DEPT.DEPTNO = a.DEPTNO WHERE 1=1 
 8 )
 9 LOOP
10 V_empno:=curr_row.empno;
11 IF V_empno>=7700 THEN 
12 dbms_output.PUT_LINE(curr_row.empno||‘,‘||curr_row.ENAME);
13 END IF; 
14 --dbms_output.PUT_LINE(curr_row.empno);
15 END LOOP;
16 EXCEPTION
17 WHEN OTHERS THEN ROLLBACK;
18 END proc_testfor;

1 SELECT e.* ,dept.* 
2 FROM EMP e RIGHT   JOIN DEPT ON DEPT.DEPTNO = e.DEPTNO;
3 
4 SELECT e.* ,dept.* 
5 FROM EMP e  LEFT   JOIN DEPT ON DEPT.DEPTNO = e.DEPTNO;
6 
7 
8 SELECT e.* ,dept.* 
9 FROM EMP e INNER   JOIN DEPT ON DEPT.DEPTNO = e.DEPTNO;

 1 MERGE INTO BS_BRAND B
 2 USING (SELECT A.* FROM (
 3 SELECT T.*,ROW_NUMBER() OVER(PARTITION BY T.BRANDNAME ORDER BY T.BRANDID DESC) RN  
 4 FROM VIEW_BRANDINFO_MODIAFY_TEMP T ) A WHERE a.rn=1) L
 5 ON ( UPPER(REPLACE(B.BRANDNAME,‘ ‘,‘‘))=UPPER(REPLACE(L.BRANDNAME,‘ ‘,‘‘)))
 6 WHEN MATCHED THEN
 7     UPDATE SET B.FORMATNAME=L.FORMATNAME,B.MAINFORMATNAME=L.MAINFORMATNAME,B.DETAILFORMATNAME=L.DETAILFORMATNAME,
 8 B.BOTTOMFORMATNAME=L.BOTTOMFORMATNAME,B.FORMATID=L.FORMATID,B.MAINFORMATID=L.MAINFORMATID,B.DETAILFORMATID=L.DETAILFORMATID,
 9 B.BOTTOMFORMATID=L.BOTTOMFORMATID,b.SECONDRECORDSTATUS=‘HISTORY‘
10 WHERE B.BRANDID IN (SELECT A.BRANDID FROM (
11 SELECT T.*,ROW_NUMBER() OVER(PARTITION BY T.BRANDNAME ORDER BY T.BRANDID DESC) RN  
12 FROM VIEW_BRANDINFO_MODIAFY_TEMP T ) A WHERE a.rn>1)

1 UPDATE POS_NEW_CONTRACT SET ISDELETE=1  where (CHANGECONTRACTID) in 
2                 (select CHANGECONTRACTID from POS_NEW_CONTRACT group by CHANGECONTRACTID having count(*) > 1) 
3                 and rowid not in (select min(rowid) from POS_NEW_CONTRACT group by CHANGECONTRACTID having count(*)>1)
4                 AND ISDELETE=0;
5 
6 --没有主键根据rowid更新

 1 SELECT e.EMPNO,e.ENAME,SAL,nvl(comm,0),nvl2(comm,1600,0), 
 2 decode(e.DEPTNO,20,‘销售部‘,30,‘市场部‘,‘其它部门‘) AS decodeDept,
 3 CASe  WHEN  e.DEPTNO=20 THEN ‘销售部‘
 4       WHEN  e.DEPTNO=30 THEN ‘市场部‘ ELSE ‘其它部门‘ 
 5       END AS caseDept   FROM EMP e;
 6       
 7 --Oracle在nvl()函数的功能上扩展，提供了nvl2()函数 nvl2()(E1, E2, E3)的功能为：
 8 --如果E1为NULL，则函数返回E3，若E1不为null，则返回E2
 9 
10 --DECODE 与CASE WHEN 的比较
11 -- 1.DECODE 只有Oracle 才有，其它数据库不支持;
12 -- 2.CASE WHEN的用法， Oracle、SQL Server、 MySQL 都支持;
13 -- 3.DECODE 只能用做相等判断,但是可以配合sign函数进行大于，小于，等于的判断,
14 -----CASE when可用于=,>=,<,<=,<>,is null,is not null 等的判断;
15 -- 4.DECODE 使用其来比较简洁，CASE 虽然复杂但更为灵活;
16 -- 5.另外，在decode中，null和null是相等的，但在case when中，只能用is null来判断

 1 一）日期函数[重点掌握前四个日期函数]
 2 1,add_months[返回日期加(减)指定月份后(前)的日期]
 3 
 4 select sysdate S1,add_months(sysdate,10) S2,
 5 add_months(sysdate,-5) S3 from dual;
 6 
 7 2,last_day [返回该月最后一天的日期] 
 8 select last_day(sysdate) from dual; 
 9 
10 3,months_between[返回日期之间的月份数]
11 select sysdate S1, months_between(‘1-4月-04‘,sysdate) S2,
12 months_between(‘1-4月-04‘,‘1-2月-04‘) S3 from dual
13 
14 4,next_day(d,day): 返回下个星期的日期,day为1-7或星期日-星期六,1表示星期日 
15 select sysdate S1,next_day(sysdate,1) S2,
16 next_day(sysdate,‘星期日‘) S3 FROM DUAL 
17 
18 5,round[舍入到最接近的日期](day:舍入到最接近的星期日)
19 select sysdate S1,
20 round(sysdate) S2 ,
21 round(sysdate,‘year‘) YEAR,
22 round(sysdate,‘month‘) MONTH ,
23 round(sysdate,‘day‘) DAY from dual
24 
25 6,trunc[截断到最接近的日期] 
26 select sysdate S1,
27 trunc(sysdate) S2,
28 trunc(sysdate,‘year‘) YEAR,
29 trunc(sysdate,‘month‘) MONTH ,
30 trunc(sysdate,‘day‘) DAY from dual
31 
32 7,返回日期列表中最晚日期
33 select greatest(‘01-1月-04‘,‘04-1月-04‘,‘10-2月-04‘) from DUAL
34 
35 8、to_char()[将日期和数字类型转换成字符类型]
36 select to_char(sysdate) s1,
37 to_char(sysdate,‘yyyy-mm-dd‘) s2,
38 to_char(sysdate,‘yyyy‘) s3,
39 to_char(sysdate,‘yyyy-mm-dd hh12:mi:ss‘) s4,
40 to_char(sysdate, ‘hh24:mi:ss‘) s5,
41 to_char(sysdate,‘DAY‘) s6 from dual;
42 9、to_date()  ‘2018-09-23 11:00:41‘
43 
44 SELECT to_date(‘2018-09-23 11:00:41‘,‘yyyy-mm-ddhh24:mi:ss‘) s1,
45 to_date(‘2018-09-23‘,‘yyyy-mm-ddhh24:mi:ss‘) s2
46  FROM DUAL ;

 1 create table test as select * from dept; --从已知表复制数据和结构
 2 create table test as select * from dept where 1=2; --从已知表复制结构但不包括数据
 3 
 4 --新增一列
 5 ALTER TABLE TEST ADD rn  NUMBER;
 6 --修改列：     
 7 alter  table TEST  rename   column   rn   to   rn1; 
 8 --修改列的类型：     
 9 alter table TEST modify rn1 varchar(200); 
10 --删除数据库一列     
11 alter table TEST drop column rn1;
12 
13 ----建表语句判断
14 declare  tableExist number;
15  begin
16  select count(1) into tableExist from user_tables where table_name=upper(‘TEST‘) ;
17  if tableExist = 0  then
18  execute immediate
19  ‘CREATE TABLE TEST(
20     BunkID NUMBER ,
21     PlazaID NUMBER ,
22     CHANGECONTRACTID NUMBER ,
23     FloorID NUMBER ,
24     ISDELETE NUMBER ,
25     BunkCode VARCHAR2(100) ,
26     BAIHUOFLAG VARCHAR2(10) ,
27     ModifyDate DATE,
28     LastUpDATE DATE )‘;
29  end if;
30  end;

 1 DECLARE
 2 
 3     MONTH_BUNKREPORTJOB NUMBER;
 4 
 5 BEGIN
 6 
 7     DBMS_JOB.SUBMIT(JOB => MONTH_BUNKREPORTJOB,
 8 
 9     WHAT => ‘PRO_ZCZL_TO_POS_BUNKDATA;‘,                          --执行的存储过程的名字
10 
11     NEXT_DATE =>to_date(‘2018-09-16 23:30:00‘,‘yyyy-mm-dd hh24:mi:ss‘),
12 
13     INTERVAL => ‘SYSDATE+1‘);     --每天运行PRO_ZCZL_TO_POS_BUNKDATAJOB一次
14 
15     COMMIT;
16 
17 END;