Oracle将结果集放入FORALL中的变量中

Question

我有以下plsql块

declare 
TYPE t_mds_ids IS TABLE OF mds.id%TYPE;
l_mds_ids t_mds_ids;
l_mds_parents t_mds_parents;
begin
SELECT id BULK COLLECT INTO l_mds_ids FROM mds;
FORALL indx IN l_mds_ids.FIRST .. l_mds_ids.LAST
select l_mds_ids(indx), ch.id_employee_parent
into l_mds_parents
FROM hierarchy_all ch
CONNECT BY ch.id_employee = prior ch.id_employee_parent
START WITH ch.id_employee = l_mds_ids(indx);
EXECUTE IMMEDIATE 'truncate table mds_hierarchy_all';
insert into mds_hierarchy_all
select * from l_mds_parents;
end;

t_mds_parents声明为

create or replace type r_mds_parents as object (
id_mds number(5,0),
id_employee number(5,0)
);
/
create or replace type t_mds_parents as table of r_mds_parents;
/

我得到一个异常ORA-00947：值不够

我真的需要在FORALL循环的每次迭代中将多行的结果集放入TABLE TYPE的变量中。我不能在l_mds_parents中使用BULK COLLECT，因为它在FORALL内部受到限制。是否只有使用临时表而不是表变量的解决方案？

Answer 1

我认为forall无法做到这一点。您可以使用嵌套循环：

declare 
TYPE t_mds_ids IS TABLE OF mds.id%TYPE;
l_mds_ids t_mds_ids;
l_mds_parents t_mds_parents;
begin
SELECT id BULK COLLECT INTO l_mds_ids FROM mds;
l_mds_parents := NEW t_mds_parents();
FOR indx IN l_mds_ids.FIRST .. l_mds_ids.LAST LOOP
FOR rec IN (
select l_mds_ids(indx) as id_employee, ch.id_employee_parent
FROM hierarchy_all ch
CONNECT BY ch.id_employee = prior ch.id_employee_parent
START WITH ch.id_employee = l_mds_ids(indx)
) LOOP
l_mds_parents.extend();
l_mds_parents(l_mds_parents.COUNT)
:= NEW r_mds_parents (rec.id_employee, rec.id_employee_parent);
END LOOP;
END LOOP;
EXECUTE IMMEDIATE 'truncate table mds_hierarchy_all';
insert into mds_hierarchy_all
select * from table(l_mds_parents);
end;
/

但是您根本不需要使用PL/SQL；使用单个层次查询，或者更简单地说，使用递归子查询分解：

insert into mds_hierarchy_all /* (id_mds, id_employee) -- better to list columns */
with rcte (id_mds, id_employee) as (
select m.id, ha.id_employee_parent
from mds m
join hierarchy_all ha on ha.id_employee = m.id
union all
select r.id_mds, ha.id_employee_parent
from rcte r
join hierarchy_all ha on ha.id_employee = r.id_employee
)
select * from rcte;

数据库<>篡改一些捏造的数据。