发布时间：2014-08-15 18:22:54
Lead()就是取当前顺序的下一条记录，相对Lag()就是取当前顺序的上一行记录。经常会有判断在一定条件下的两条记录之间的时间差这样的需求。 语法结构：lead(value_expr [,offset][,default]) over([query_partition_clause] order by Order_by_clause)参数说明：value_expr 值表达式，通常是.........【阅读全文】
发布时间：2014-08-15 18:08:58
with temp as( select 'China' nation ,'Guangzhou' city from dual union all select 'China' nation ,'Shanghai' city from dual union all select 'China' nation ,'Beijing' city from dual union all select 'USA' nation ,'New York' city fr.........【阅读全文】
发布时间：2013-12-10 11:42:18
Autotrace Setting ResultSET AUTOTRACE OFFNo AUTOTRACE report is generated. This is the default.SET AUTOTRACE ON EXPLAINThe AUTOTRACE report s.........【阅读全文】
发布时间：2013-12-04 18:01:32
The difference between utlchain.sql and utlchn1.sql is the column head_rowid data type:::::::::::::::utlchain.sql::::::::::::::create table CHAINED_ROWS ( owner_name varchar2(30), table_n.........【阅读全文】
发布时间：2013-11-25 15:34:03
select level, max('col_name') from my_tablewhere level = '&n'connect by prior ('col_name') > 'col_name')group by level;-- Example :---- Given a table called emp with the following columns:-- id number.........【阅读全文】
