所以我们想要一个子句: CONNECT BY PRIOR parent = child 。这意味着“前一行的父级等于该行的子级” 所以查询看起来像: SELECT child, parent, level FROM family_tree CONNECT BY PRIOR parent = child START WITH parent = 'John' SQL 小提琴示例 (这是一个有点奇怪的例子,因为实际的孩子有两个父母,...
I've a table with hierarchical data relationship (parent-child) contained in one table.How i can query the table and return the records sorted by its hierarchical level?To those who are familiar with Oracle, i'm looking for the same thing that 'Connect by' does....
PARENT_ID, NAME)values(,null,'中国');insertintoarea_test(ID, PARENT_ID, NAME)values(,1,'河南省');insertintoarea_test(ID, PARENT_ID, NAME)values(,1,'北京市');insertintoarea_test(ID, PARENT_ID, NAME)values(,11,'郑州市');insertintoarea_test(ID, PARENT...
parentcursor包含了SQL TEXT和相关的hash value,v$sqlarea中的每一行代表了一个parent cursor,根据address表示了其内存地址。 childcursor包含了SQL的metadata,即使得这个SQL可以执行的所有相关信息,如OBJECT和权限,优化器设置,执行计划等。v$sql中中 的每一行表示了一个child cursor,根据hash value和address与parent curso...
huckets 指向library chache object handle,handle 指向一个library cache object,即heap 0. 这个就是parent。 heap 0里保存了hash 值和所有child cursor 的地址。 parent cursor 和child cursor 结构是完全一样的。 当第二次执行相同的SQL 时, 因为第一次硬解析时已经生成了parent cursor和child cursor。 所以在...
1. 用途 强行启用并行度来执行当前SQL。这个在Oracle 9i之后的版本可以使用,之前的版本现在没有环境进行测试。也就是说,加上这个说明,可以强行启用Oracle的多线程处理功能。举例的话,就像电脑装了多核的CPU,但大多情况下都不会完全多核同时启用(2核以上的比较明显)
sql oracle recursive-query self-join 我有这些数据和预期结果: Data Expected Result No A B A B 1 10 500 10 500 2 10 c=20 20 400 3 20 400 30 600 4 30 600 30 700 5 30 c=40 30 800 6 30 c=50 40 700 7 40 700 50 900 8 50 c=60 60 900 9 60 c=70 70 900 10 70 900 ...
COLUMN tree FORMAT A20 WITH t1(id, parent_id, lvl) AS ( -- Anchor member. SELECT id, parent_id, 1 AS lvl FROM tab1 WHERE parent_id IS NULL UNION ALL -- Recursive member. SELECT t2.id, t2.parent_id, lvl+1 FROM tab1 t2, t1 WHERE t2.parent_id = t1.id ) SEARCH DEPTH ...
Navigate backward into or out of tree control Shift+Tab Expand (if item contains children) Right Arrow Collapse (if item contains children) Left Arrow Move to parent from child (if expanded) Left Arrow Move to child from parent (if already expanded) Right Arrow Move up/down one item...
(child table) for a reconciliation event.This API is supported for backward compatibility.Functionally, the processing *is same as that of addMultiAttributeData, it just provides a wrapper over addMultiAttributeData and delegate call to this method.In 9.1 this was used to invoke SQL directly ...