复合列null问题
outer join语句
cbo,rbo
left right,full join
grouping
GroupingSyntaxPurposeGROUPING distinguishes superaggregate rows from regular grouped rows. GROUP&nb...
关于游标
http://www.itpub.net/thread-1394528-1-1.html游标分为隐式、显式、REF三种游标。而隐式游标和显式游标又都属于静态游标,REF游标属于动态游标。静态游标和动态游标的最大区别在于静态游标是在运行前将游标变量和S...
pivot and unpivot
转载于http://dev.21tx.com/2008/12/16/13997.htmlPivot 如您所知,关系表是表格化的,即,它们以列-值对的形式出现。假设一个表名为 CUSTOMERS.SQL> desc customersName ...
GROUPING_ID
1.SyntaxGROUPING_ID(expr [, expr ]...)2.PurposeGROUPING_ID returns a number corresponding to the GROUPING bit...
关于grouping,grouping_id,grouping sets()的练习
2011-6-25 GROUPING SETS作者:Kim Berg Hansen难度:中我创建了如下的表并填入数据:CREATE TABLE plch_sales( product VARCHAR2(10), country VARCH...
MERGE
1、PurposeUse the MERGE statement to select rows from one or more sources for update or insertion into a table...
oracle ref cursor的介绍
转自http://space.itpub.net/8102208/viewspace-369116REF CURSOR分两种,Strong REF CURSOR 和 Weak REF CURSOR。Strong REF CURSOR:指定retrun type,CURSOR变量的类型必须和...
行列转换
http://space.itpub.net/23278472/viewspace-689961有许多内容是转载此处的 。假如有如下表,其中各个i值对应的行数是不定的SQL> select * from t;IA D———- ———- ——————-1 b 2008-03-27 10:55:421 a2008...
Oracle:Rank,Dense_Rank,Row_Number比较
转载于http://trailblizer.blog.163.com/blog/static/59630364200982792143361/一个员工信息表Create Table EmployeeInfo (CODE Number(3) Not Null,EmployeeName varchar2(15),DepartmentID Number(3),Salary NUMBE...
层次查询
转载于http://blog.csdn.net/nsj820/article/details/6299276层次查询的概念语法格式:select [level], column, expr... from table [where condition] start with condi...
oracle keep用法
转自http://blog.csdn.net/a9529lty/article/details/6534564看到很多人对于keep不理解,这里解释一下!Returns the row ranked first using DENSE_RANK2种取值:DENSE_RANK FIRSTDENSE_RANK LAST在keep (DENSE_RANK...
视图合并
来源于en-core的个人空间