在关系数据库中查找“一对三”链接
Finding "1-to-3" links in a relational database
我敢肯定有一个我不知道的术语，但我们称之为寻找“1 对 3”link。假设我有一个像这样的 table：
ID Src Src_Field Tgt Tgt_Field
1 Table1 Field_A Table2 Field_D
2 Table1 Field_B Table2 Field_E
3 Table1 Field_C Table2 Field_F
4 Table2 Field_D Table3 Field_G
5 Table2 Field_E Table3 Field_H
6 Table2 Field_F Table3 Field_I
我希望最终结果如下所示：
Table1 Field_A Table2 Field_D Table3 Field_G
Table1 Field_B Table2 Field_E Table3 Field_H
Table1 Field_C Table2 Field_F Table3 Field_I
我不是在找人帮我写查询，而是在找这个叫什么，算法的 link 等。我正在努力寻找这些links 并将它们配对：
1 => 2
2 => 3
所以我得到：
1 => 2 => 3
因此我的术语是“一对三”link。实际的关系数据库并不重要。我主要是想了解如何执行此操作。
我将其描述为 hierarchical database model。
A hierarchical database model is a data model in which the data is
organized into a tree-like structure.
A recursive join 将用于获取您提供的结果。
The recursive join is an operation used in relational databases, also
sometimes called a "fixed-point join". It is a compound operation that
involves repeating the join operation, typically accumulating more
records each time, until a repetition makes no change to the results
(as compared to the results of the previous iteration).
我敢肯定有一个我不知道的术语，但我们称之为寻找“1 对 3”link。假设我有一个像这样的 table：
ID Src Src_Field Tgt Tgt_Field
1 Table1 Field_A Table2 Field_D
2 Table1 Field_B Table2 Field_E
3 Table1 Field_C Table2 Field_F
4 Table2 Field_D Table3 Field_G
5 Table2 Field_E Table3 Field_H
6 Table2 Field_F Table3 Field_I
我希望最终结果如下所示：
Table1 Field_A Table2 Field_D Table3 Field_G
Table1 Field_B Table2 Field_E Table3 Field_H
Table1 Field_C Table2 Field_F Table3 Field_I
我不是在找人帮我写查询，而是在找这个叫什么，算法的 link 等。我正在努力寻找这些links 并将它们配对：
1 => 2
2 => 3
所以我得到：
1 => 2 => 3
因此我的术语是“一对三”link。实际的关系数据库并不重要。我主要是想了解如何执行此操作。
我将其描述为 hierarchical database model。
A hierarchical database model is a data model in which the data is organized into a tree-like structure.
A recursive join 将用于获取您提供的结果。
The recursive join is an operation used in relational databases, also sometimes called a "fixed-point join". It is a compound operation that involves repeating the join operation, typically accumulating more records each time, until a repetition makes no change to the results (as compared to the results of the previous iteration).