1、脚本
create table T_TREE(
S_ID NUMBER,
F_ID NUMBER,
S_NAME VARCHAR2(20)
);
comment on column T_TREE.S_ID
is '本节点ID';
comment on column T_TREE.F_ID
is '父节点ID';
comment on column T_TREE.S_NAME
is '本节点名称';
insert into t_tree values(1,null,'root');
insert into t_tree values(2,1,'node-010');
insert into t_tree values(3,1,'node-020');
insert into t_tree values(4,3,'node-011');
insert into t_tree values(5,4,'node-011');
commit;
2、用SYS_CONNECT_BY_PATH执行SQL语句
SELECT CONNECT_BY_ISLEAF ISLEAF,
S_NAME,
LTRIM(SYS_CONNECT_BY_PATH(S_NAME, '$'), '$') PATH
FROM T_TREE
CONNECT BY PRIOR S_ID = F_ID
START WITH F_ID IS NULL;
其实SYS_CONNECT_BY_PATH这个函数是oracle9i才新提出来的!它一定要和connect by子句合用!
第一个参数是形成树形式的字段,第二个参数是父级和其子级分隔显示用的分隔符!
START WITH 代表你要开始遍历的的节点!CONNECT BY PRIOR 是标示父子关系的对应!
其中CONNECT_BY_ISLEAF ISLEAF 是判断数据是否是叶节点,如果是的话 值是1,还有子节点的话值是0;
3、查询结果