Question

因此，我正在尝试从只读数据库中编写查询，该查询将基本向我展示父值和子值之间的关系以及其他表中的一些其他信息。

我几乎在需要的地方找到了查询，但是正在用相应的名称和电子邮件替换一些值而感到苦恼

基本上，我试图反映在电子邮件和凭据表中显示的名称和电子邮件，该名称和电子邮件与在“父母姓名”和“父母电子邮件”列的当前位置显示的相应AcctID相对应。即。用“约翰·史密斯”代替父母姓名中的“ 1a2b”，用“ test @ test”代替父母电子邮件中的“ 1a2b”

我一开始尝试了一个案例陈述，但我想这可能与我所缺少的联接有关。

在此先感谢任何帮助人员。

Answer 1

您只需再次连接到credentials和email表即可提取父数据：

select
    cr1.data                as "Parent Name",
    e1.email                as "Parent Email",
    cr.data                 as "Child Name",
    e.email                 as "Child Email",
    sum(a.amount)           as "Amount",
    (sum(a.amount)*2.5/100) as "% of Amount"

from 
    email e
join
    class c
        on e.AcctID = c.AcctID
left join
    relationship r 
        on c.AcctID = r.child
left join
    amount a
        on e.AcctID = a.AcctID
left join
    credentials cr
        on e.AcctID = cr.AcctID and cr.value = 1
left join
    credentials cr1
        on r.Parent = cr1.AcctID and cr1.value = 1
left join
    email e1
        on e1.AcctId = r.Parent
where
    c.relationship = 'child'
group by 
    cr1.data, e1.email, cr.data, e.email
order by
    cr1.data

输出：

Parent Name     Parent Email    Child Name  Child Email     Amount  % of Amount
                so@so                       add@add         10.36   0.259000
John Smith      Test@Test       Jane Smith  email@email     24.72   0.618000

Demo on dbfiddle

Answer 2

如果我的理解正确，您只需join表email两次。查询看起来像这样：

select r.parent as "Parent Name",
       ep.email as "Parent Email",
       cr.data as "Child Name",
       ec.email as "Child Email",
       sum(a.amount) as "Amount",
       (sum(a.amount)*2.5/100) as "% of Amount"
from class c left join
     relationship r 
     on c.AcctID = r.child left join
     email ec
     on ec.AcctId = r.child left join
     email ep
     on ep.AcctId = r.parent left join
     amount a
     on c.AcctID = a.AcctID left join
     credentials cr
     on c.AcctID = cr.AcctID and cr.value = 1
where c.relationship = 'child'
group by r.Parent, ep.email, cr.data, ec.email
order by r.Parent;

Here是您的db <>小提琴，带有固定的查询。

请注意，这也可以解决您的join条件（因此一旦引入email表，就不会有任何内容加入）。而且还简化了group by键。

mysql-用来自2个不同表的对应值替换列的值

2 个答案: