DB2 转Oracle
DB2 转Oracle
某天是星期几的函数
DB2:
select a.yyxe,a.zblb,a.ysdm,a.daynum,b.zjxm from zy_yspb a ,zy_zjlb b where a.ysdm=b.id and a.ksdm=10000 order by abs( a.daynum -DAYOFWEEK(current date)+1) desc,a.daynum,a.zblb
sql.executeQuery:ORA-00936: 缺失表达式
Oracle :
select a.yyxe,a.zblb,a.ysdm,a.daynum,b.zjxm from zy_yspb a ,zy_zjlb b where a.ysdm=b.id and a.ksdm=10000 order by abs( a.daynum -to_char(sysdate,'D')+1) desc,a.daynum,a.zblb
to_char 和to_date的用法
DB2:
select count(*) as yyrs from zy_zzd where zblb=2 and zzys=10000 and zzrq >='2009-08-21 00:00:00' and zzrq <='2009-08-21 23:59:59' and -DAYOFWEEK(current date)-1=2
Oracle :
select count(*) as yyrs from zy_zzd where zblb=2 and zzys=10000 and zzrq >=to_date('2009-08-21 00:00:00','yyyy-mm-dd hh24:mi:ss') and zzrq <=to_date('2009-08-21 23:59:59','yyyy-mm-dd hh24:mi:ss') and to_char(zzrq,'D')-1=2
ZCJGMC，ZRJGMC，SHYSMC，ZRKSMC，CARDID，ZCKSMC
相关文档：
http://topic.csdn.net/t/20040818/16/3287013.html
1.基本结构
CREATE OR REPLACE PROCEDURE 存储过程名字
(
参数1 IN NUMBER,
参数2 IN NUMBER
) IS|AS
变量1 INTEGER :=0;
变量2 DATE;
BEGIN
END 存储过程名字
说明：is也可换成as
2.SELECT INTO STATEMENT
& ......
在SQL语句优化过程中，我们经常会用到hint,现总结一下在SQL优化过程中常见Oracle HINT的用法：
1. /*+ALL_ROWS*/
表明对语句块选择基于开销的优化方法,并获得最佳吞吐量,使资源消耗最小化.
例如:
SELECT /*+ALL+_ROWS*/ EMP_NO,EMP_NAM,DAT_IN from BSEMPMS WHERE EMP_NO=’SCOTT’;
2. /*+FIRST_ROWS*/
表 ......
-- 笔记中部分内容
SQL> create table tt2 as select * from employee;
Table created.
SQL> drop table tt2;
Table dropped.
SQL> select * from tt2;
select * from tt2
*
ERROR at line 1:
ORA-00942: table or view does not exist
SQL> flashback table tt2 to before drop;
Flashback comp ......
http://www.ej38.com/showinfo/Oracle-108709.html
Oracle 10g statistic数据统计,Oracle会根据这些统计信息来决定是走RBO(Rule-BasedOptimization)，还是走CBO(Cost-BasedOptimization)，会去选择哪种执行计划更划算,影响是否走相关的索引等.如果是CBO的话，它依靠准确的（或者说比较准确的）统计信息来产生优化的� ......
oracle表空间操作详解
一、建立表空间
CREATE TABLESPACE data01
DATAFILE '/oracle/oradata/db/DATA01.dbf' SIZE 500M
UNIFORM SIZE 128k;
二、建立UNDO表空间
CREATE UNDO TABLESPACE UNDOTBS02
DATAFILE '/oracle/oradata/db/UNDOTBS02.dbf' SIZE 50M
#注意：在OPEN状态下某些时刻只能用一个UNDO表空间，如果� ......
