oracle 常用函数积累

这些天的工作很多都是围绕着oracle函数来展开的，这里来总结一下这些天在工作中使用过的函数。其实也算不上总结，就是把这些日子对于oracle的使用做一个简单的知识罗列。

• 以管道化表函数方式返回数据

  --创建指定数据类型的对象

  create type row_typedepluju as object (rootid NUMBER(19),projectid NUMBER(19));

  --创建指定数据类型的对象table

  create type table_typedepluju as table of row_typedepluju;

  create or replace function getlujudepinfobyaccount(useraccount in VARCHAR2)

  return table_typedepluju pipelined as v row_typedepluju;

  begin

  --遍历存放数据

  for myrowdep in (

  -- 查出路局/客专所有的项目id 及根部门id

  select t.id as rootid,pinfo.id as projectid from base_security_department t

  left join pbs_projectinfo pinfo on pinfo.constructiondep_id = t.id

  where t.useflag = 1 and t.grade in (60,130)

  start with t.id=(

  select a.departmentid from base_security_userinfo a where a.account=useraccount)

  connect by prior t.parentid=t.id

  ) loop

  v :=row_typedepluju(myrowdep.rootid,myrowdep.projectid);

  pipe row (v);

  end loop;

  return ;

  end;

• minus函数返回表的差集

  --取得逗号分隔后的数据中，在关联表中不存在的部分

  insert into base_security_deptproject b (departmentid,projectid) select v.DEPARTMENTID,v.PROJECTID from (select * from

  --选取切割后不为空的数据

  (select c.DEPARTMENTID,c.PROJECTID from (

  --根据逗号切割数据，一行转多行

  --temp0为临时表，20为可接受的逗号数量

  with temp0 as (select LEVEL lv from dual CONNECT BY LEVEL <= 20)

  --切割

  select DEPARTMENTID,substr(

  t.vals,instr(t.vals, ‘,‘, 1, tv.lv) + 1,

  instr(t.vals, ‘,‘, 1, tv.lv + 1) -(

  instr(t.vals, ‘,‘, 1, tv.lv) + 1)

  ) AS projectid from

  --选取待分解的数据，即在用的，指挥部。并取得“,”号数量

  (select id as DEPARTMENTID, PROJECTIDS AS vals,

  length(PROJECTIDS ) - (nvl(length(REPLACE(PROJECTIDS, ‘,‘)), 0)+1) AS cnt

  from BASE_SECURITY_DEPARTMENT g where g.GRADE=‘145‘ and g.USEFLAG=‘1‘ and g.PROJECTIDS is not NULL) t

  left join temp0 tv

  on tv.lv <= t.cnt) c where c.PROJECTID is not NULL)

  --取差集

  MINUS

  -- 关联表中的数据

  (select t.DEPARTMENTID as DEPARTMENTID,"TO_CHAR"(t.PROJECTID) from BASE_SECURITY_DEPTPROJECT t)) v

• start with connect 方式展现整棵树

select * from base_security_department t connect by prior t.parentid=t.id start with t.id=2400;

• substr

substr(字符串,截取开始位置,截取长度) //返回截取的字

`select decode(max(substr(t.bscode,length(t.bscode)-1,length(t.bscode))),null,0,max(substr(t.bscode,length(t.bscode)-1,length(t.bscode)))+1) as codenum from base_security_department t where t.useflag=1 and t.bscode like ‘XKHJ01SG07SY__‘;`

• nextval

nextval的值是每调用一次就增加一次

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