例:
13:38:20 SQL> desc ttree;
名称 空? 类型
----------------------------------------- -------- ----------------------------
ID VARCHAR2(10)
PID VARCHAR2(10)
PRICE NUMBER13:38:20 SQL> select * from ttree;ID PID PRICE
---------- ---------- ----------
B A 20
D B 3
E B 5
G D 2
C A 1
F C 2
G C 5
G H 3已选择8行。已用时间: 00: 00: 00.31
13:38:23 SQL> select * from ttree start with id='B' connect by prior id=pid;ID PID PRICE
---------- ---------- ----------
B A 20
D B 3
G D 2
E B 5已用时间: 00: 00: 00.31
13:38:59 SQL>
13:38:20 SQL> desc ttree;
名称 空? 类型
----------------------------------------- -------- ----------------------------
ID VARCHAR2(10)
PID VARCHAR2(10)
PRICE NUMBER13:38:20 SQL> select * from ttree;ID PID PRICE
---------- ---------- ----------
B A 20
D B 3
E B 5
G D 2
C A 1
F C 2
G C 5
G H 3已选择8行。已用时间: 00: 00: 00.31
13:38:23 SQL> select * from ttree start with id='B' connect by prior id=pid;ID PID PRICE
---------- ---------- ----------
B A 20
D B 3
G D 2
E B 5已用时间: 00: 00: 00.31
13:38:59 SQL>
ID Field 标示每个节点的ID
ParentID Field 标示该节点父节点的ID,如果该值为0,则为根节点
注:这两个Field的定义类型和长度是相同的。其它字段可以任意设计了^_^SQL:
已知一个根节点的ID=123,那么
select * from table where ParentID=123;
connect by
我怎么从来没见过呀。大虾给点详细解释?