oracle笔记 (procedure 递归构造树)

--树状结构存储
create table article
(
	id number primary key,
	cont varchar2(4000),
	pid number,
	isleaf number(1), --0代表非叶子节点 1代表叶子节点
	alevel number(2) --级别
);

insert into article values(1,'蚂蚁大战大象',0,0,0); 
insert into article values(2,'大象被打趴下了',1,0,1); 
insert into article values(3,'蚂蚁也不好过',2,1,2); 
insert into article values(4,'瞎说',2,0,2); 
insert into article values(5,'没有瞎说',4,1,3); 
insert into article values(6,'怎么可能',1,0,1); 
insert into article values(7,'怎么没有可能',6,1,2); 
insert into article values(8,'可能性是很大的',6,1,2); 
insert into article values(9,'大象进医院了',2,0,2); 
insert into article values(10,'护士是蚂蚁',9,1,3); 




--构造哦树状结构(递归)
create or replace procedure p(v_id article.id%type, v_level binary_integer)
	is
	cursor c is select * from article where pid = v_id;
	v_preStr varchar2(1024) := '';
begin
	for i in 1..v_level loop
		v_preStr := v_preStr || '----';
	end loop;
	for v_article in c loop
		dbms_output.put_line(v_preStr || v_article.cont);
		if (v_article.isleaf = 0) then
			p(v_article.id,v_level + 1);			
		end if;
	end loop;
end;
SQL> exec p(0,0)
蚂蚁大战大象
----大象被打趴下了
--------蚂蚁也不好过
--------瞎说
------------没有瞎说
--------大象进医院了
------------护士是蚂蚁
----怎么可能
--------怎么没有可能
--------可能性是很大的

create or replace procedure p(v_empno emp.empno%type,v_level binary_integer)
	is
	cursor c is select * from emp where mgr = v_empno;
	v_preStr varchar2(1024) := '';
begin
	for i in 1..v_level loop
		v_preStr := v_preStr || '----';
	end loop;
	for v_emp in c loop
		dbms_output.put_line( v_preStr || v_emp.ename );
		p(v_emp.empno,v_level+1);
	end loop;
end;
--树状结构存储
create table article
(
	id number primary key,
	cont varchar2(4000),
	pid number,
	isleaf number(1), --0代表非叶子节点 1代表叶子节点
	alevel number(2) --级别
);

insert into article values(1,'蚂蚁大战大象',0,0,0); 
insert into article values(2,'大象被打趴下了',1,0,1); 
insert into article values(3,'蚂蚁也不好过',2,1,2); 
insert into article values(4,'瞎说',2,0,2); 
insert into article values(5,'没有瞎说',4,1,3); 
insert into article values(6,'怎么可能',1,0,1); 
insert into article values(7,'怎么没有可能',6,1,2); 
insert into article values(8,'可能性是很大的',6,1,2); 
insert into article values(9,'大象进医院了',2,0,2); 
insert into article values(10,'护士是蚂蚁',9,1,3); 




create or replace procedure p
	is
	 cursor c is
		select * from emp2 for update;
begin
	insert into article values(1,'蚂蚁大战大象',0,0,0); 
	insert into article values(2,'大象被打趴下了',1,0,1); 
	insert into article values(3,'蚂蚁也不好过',2,1,2); 
	insert into article values(4,'瞎说',2,0,2); 
	insert into article values(5,'没有瞎说',4,1,3); 
	insert into article values(6,'怎么可能',1,0,1); 
	insert into article values(7,'怎么没有可能',6,1,2); 
	insert into article values(8,'可能性是很大的',6,1,2); 
	insert into article values(9,'大象进医院了',2,0,2); 
	insert into article values(10,'护士是蚂蚁',9,1,3); 
	commit;
end;

--构造哦树状结构
create or replace procedure p(v_id article.id%type, v_level binary_integer)
	is
	cursor c is select * from article where pid = v_id;
	v_preStr varchar2(1024) := '';
begin
	for i in 1..v_level loop
		v_preStr := v_preStr || '----';
	end loop;
	for v_article in c loop
		dbms_output.put_line(v_preStr || v_article.cont);
		if (v_article.isleaf = 0) then
			p(v_article.id,v_level + 1);			
		end if;
	end loop;
end;
SQL> exec p(0,0)
蚂蚁大战大象
----大象被打趴下了
--------蚂蚁也不好过
--------瞎说
------------没有瞎说
--------大象进医院了
------------护士是蚂蚁
----怎么可能
--------怎么没有可能
--------可能性是很大的

create or replace procedure p(v_empno emp.empno%type,v_level binary_integer)
	is
	cursor c is select * from emp where mgr = v_empno;
	v_preStr varchar2(1024) := '';
begin
	for i in 1..v_level loop
		v_preStr := v_preStr || '----';
	end loop;
	for v_emp in c loop
		dbms_output.put_line( v_preStr || v_emp.ename );
		p(v_emp.empno,v_level+1);
	end loop;
end;
SQL> exec p(7839,0)
JONES
----SCOTT
--------ADAMS
----FORD
--------SMITH
BLAKE
----ALLEN
----WARD
----MARTIN
----TURNER
----JAMES
CLARK
----MILLER