Question

我试图将两个表合并在一起并保持一个是另一个表的子节点的事实。我想表明它有一个父级，同时仍然保持父级的唯一值。

这里有我的关系： subdomain.domain_id与（你猜对了）domain.id

有关

我的表格示例

域：

id | name | description | validator | need | need_amount
---|------|-------------|-----------|------|-------------
5  | prog | this iss..  | 6         | low  | 5

子域

id | name | description | validator | domain_id | need | need_amount
---|------|-------------|-----------|-----------|------|------------
5  | java | java is...  | 10        | 5         | high | 10
6  | c++  | c++...      | 9         | 5         | high | 10

我希望能够看到

id | domain_name | subdomain_name | description | validator | need | need_amount
---|-------------|----------------|-------------|-----------|------|-------------
5  | prog        | null           | this iss..  | 6         | low  | 5
5  | prog        | java           | this is...  | 10        | high | 10
6  | prog        | c++            | this is..   | 9         | high | 10

或者像这样，（理想情况是上面的那个）

id | name         | description | validator | need | need_amount
---|--------------|-------------|-----------|------|------------
5  | prog         | this iss..  | 6         | low  | 5
5  | prog - java  | java is...  | 10        | high | 10
6  | prog - c++   | c++...      | 9         | high | 10

任何想法???可能吗？谢谢！

感谢@Pradeep

SELECT id,
       name AS domain_name,
       NULL AS subdomain_name,
       description,
       validator,
       need,
       need_amount
FROM   domain 
UNION ALL
SELECT a.id,
       b.name AS domain_name,
       a.name            AS subdomain_name,
       a.description,
       a.validator,
       a.need,
       a.need_amount
FROM   subdomain a join domain b on a.domain_id=b.id

Answer 1

试试这个。

SELECT id,
       name AS domain_name,
       NULL AS subdomain_name,
       description,
       validator,
       need,
       need_amount
FROM   parent 
UNION ALL
SELECT a.id,
       b.domain_name AS domain_name,
       a.name            AS subdomain_name,
       a.description,
       a.validator,
       a.need,
       a.need_amount
FROM   child a join parent b on a.domain_id=b.domain_id

如何合并两个表，其中一个是另一个的父表？

1 个答案: