这些,test表中id从3开始,中间缺5,7,9,13,17,看我们的sql能否把它们找出来。 select b.seq from (select seq from (select level as seq from dual connect by level<=(select max(id) from test)) a where a.seq>=(select min(id) from test)) b where b.seq not in (select id from test) ...
1WITHAAS2(SELECTMAX(LEVEL)+1LVL3FROMEMPE4CONNECTBYPRIORE.MGR=E.EMPNO5STARTWITHE.EMPNO=78766ORDERBYLEVELDESC)7SELECTA.LVL最高等级加1,8LEVEL当前等级,9A.LVL-LEVEL优化后等级,10E.*FROMA,11EMPECONNECTBYPRIORE.MGR=E.EMPNOSTARTWITHE.EMPNO=7876ORDERBYLEVELDESC 1. 2. 3. 4. 5. 6. 7. 8. 9...
对于层次查询如果用order by排序,比如order by last_name则是先做完层次获得level,然后按last_name 排序,这样破坏了层次,比如特别关注某行的深度,按level 排序,也是会破坏层次的。在oracle10g中,增加了siblings 关键字的排序。 语法:order siblings by <expre> 它会保护层次,并且在每个等级中按expre排序。 1SELECT...
主要是通过level进行group by select count(level) from emp e connect by prior e.empno = e.mgr start with e.mgr is null group by level; COUNT(LEVEL) --- 1 3 2 8 3、oracle 10g提供了一个简单的connect_by_isleaf=1, 0 表示非叶子节点 select level as 等级, connect_by_isleaf as 是否是...
select a.*,level from persons.dept a start with paredeptid=0 connect by prior deptid=paredeptid 再次复习一下:start with ...connect by 的用法, start with 后面所跟的就是就是递归的种子。 递归的种子也就是递归开始的地方 connect by 后面的"prior" 如果缺省:则只能查询到符合条件的起始行,并不进行...
在SELECT命令中使用CONNECT BY 和蔼START WITH 子句可以查询表中的树型结构关系。其命令格式如下: SELECT 。。。 CONNECT BY {PRIOR 列名1=列名2|列名1=PRIOR 裂名2} [START WITH]; 其中:CONNECT BY子句说明每行数据将是按层次顺序检索,并规定将表中的数据连入树型结构的关系中。PRIORY运算符必须放置在连接关...
CONNECT BY是Oracle实现递归处理的SQL写法,DWS不支持CONNECT BY语法,但是有类似的WITH RECURSIVE语法可以实现递归逻辑,下面通过几个case描述CONNECT BY迁移到DWS的改写语法。 注意: case4中涉及connect_by_root、sys_connect_by_path、伪劣level相关逻辑 case4中涉及CONNECT BY前有WHERE条件的场景,此场景及其特殊,请详细...
ConnectBy、Level、StartWith的使⽤ORACLE--Connect By、Level、Start With的使⽤(Hierarchical query-层次查询)Syntax 1CONNECT BY [NOCYCLE] <condition> START WITH <condition> Syntax 2START WITH <condition> CONNECT BY [NOCYCLE] <condition> 参考⽹址:http://asktom.oracle.com/pls/asktom/f?p=100...
connect by level<=length(pi_column)-length(replace(pi_column,','))+1; 1. 2. 3. 4. 5. 6. 7. 8. 用游标 open r_cur for 上面代码 然后 提取到字符数组中 FETCH r_cur bulk collect into lv_sql; 1. 数组声明和初始化: lv_sql type_array :=type_array(); ...
1 AS instrument_level, 0 AS cycle_error, 2670 AS ss_id, s2.thekey, i.status, i.bas_instrument_id AS start_val FROM sdifin.ogg_ets_bas_instrument_t_2670 i LEFT JOIN sdifin.ogg_sectype_2360 s2 ON upper(trim(i.instrument_name)) = upper(trim(s2.name)) ...