I have a bunch of objects in a flat structure. These objects have an ID and a ParentID property so they can be arranged in trees. They are in no particular order. Each ParentID property does not necessarily matches with an ID in the structure. Therefore their could be several trees emerging from these objects. … Read more
I have a MySQL table which is as follows: id name parent_id 19 category1 0 20 category2 19 21 category3 20 22 category4 21 … … … Now, I want to have a single MySQL query to which I simply supply the id [for instance say id=19] then I should get all its child ids … Read more
Assume you have a flat table that stores an ordered tree hierarchy: Id Name ParentId Order 1 ‘Node 1’ 0 10 2 ‘Node 1.1’ 1 10 3 ‘Node 2’ 0 20 4 ‘Node 1.1.1’ 2 10 5 ‘Node 2.1’ 3 10 6 ‘Node 1.2′ 1 20 Here’s a diagram, where we have [id] Name. Root … Read more
Good Overviews Generally speaking, you’re making a decision between fast read times (for example, nested set) or fast write times (adjacency list). Usually, you end up with a combination of the options below that best fit your needs. The following provides some in-depth reading: One more Nested Intervals vs. Adjacency List comparison: the best comparison … Read more
