甲骨文的Apex树三层以上

Question

从来就得到了下面的SQL代码来生成APEX树：

select 1 as status, 1 pid, 'Fehlermeldungen' as titel, null as icon, '1' as value, NULL as tooltip, NULL as link from dual 
union 
select -1 as status, 2 pid, k.kname as titel, NULL as icon, k.knr||'0' as value, NULL as tooltip, NULL as link from kunde k where 
(select count(fmtext) from fehlermeldung f where f.knr = k.knr) > 0 
union 
select 0 as status, 3 pid, fmtext as titel, NULL as icon, k.knr||fmnr as value, NULL as tooltip, null as link from kunde k, fehlermeldung f where f.knr = k.knr 
order by value 

现在，我想添加一个第四层，但如果我试图让另一个工会当pid = 4时，条目附加到最后的选择。 我该如何管理？

Answer 1

首先，我试着重新格式化你的代码。看来你所描述的应该可以正常工作。我假设你试过这样的事情：

select 1 as status, 1 pid, 'Fehlermeldungen' as titel, null as icon, '1' as value, 
     NULL as tooltip, NULL as link from dual 
union 
select -1 as status, 2 pid, k.kname as titel, NULL as icon, k.knr||'0' as value, 
     NULL as tooltip, NULL as link from kunde k 
where (select count(fmtext) from fehlermeldung f where f.knr = k.knr) > 0 
union 
select 0 as status, 3 pid, fmtext as titel, NULL as icon, k.knr||fmnr as value, 
     NULL as tooltip, null as link from kunde k, fehlermeldung f 
where f.knr = k.knr 
-- begin my new lines... 
union 
select 0 as status, 4 pid, 'blank' as titel, NULL as icon, '4' as value, 
     NULL as tooltip, null as link from dual 
-- end my new lines... 
order by 5 

是否有可能你插入了额外的SELECT错误的地方？告诉我们你做了什么，这将更容易排除故障。