Problem:
Suppose you have a bill of materials (BOM) table with items and their parent IDs. The goal is to retrieve a hierarchical representation of the items in the form of a tree structure. Using a typical single-level query or a recursive function may be inefficient.
Solution:
The SQL language in MySQL does not support recursive queries natively. To overcome this limitation, one can create custom Stored Procedures (SPs) to achieve tree traversal functionality.
Proposed SPs:
The following SPs can be used to traverse the BOM tree:
Usage:
To use the SPs, follow these steps:
Example:
For example, if you have a BOM table with the following data:
+----+------+ | item | parent | +----+------+ | 1 | 0 | | 2 | 1 | | 3 | 1 | | 4 | 3 | | 76 | 3 | +----+------+
Calling GetFamilyTree(1) will return the following hierarchical representation:
[ { "item": 1, "children": [ { "item": 2, "children": [] }, { "item": 3, "children": [ { "item": 4, "children": [] }, { "item": 76, "children": [] } ] } ] } ]
This representation provides all the child branches in the tree, allowing for efficient retrieval of item relationships.
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