If you’re lucky enough to be using SQLite 3.8.3 or higher then you do have access to recursive and non-recursive CTEs using WITH: Thanks to lunicon for letting us know about this SQLite update. In versions prior to 3.8.3, SQLite didn’t support recursive CTEs (or CTEs at all for that matter) so there was no …
Store IDs of the objects in a hash table mapping to the specific object. Enumerate through all the objects and find their parent if it exists and update its parent pointer accordingly. In C#: class MyObject { // The actual object public int ParentID { get; set; } public int ID { get; set; } …
Since you want the elements in the TreeView to have a list of children that consists of both Categories Products, you will want your Category ViewModel to have a collection that consists of both Categories and Products. For example, you could use a CompositeCollection to combine your existing collections: public class Category { public string …
CREATE TABLE #MY_TABLE ( ID INT ,ID_FATHER INT ,COL_X INT ) CREATE TABLE #MY_TABLE_BIS ( MY_ID INT ,X VARCHAR(50) ) CREATE TABLE #OTHER_TABLE ( MY_ID INT ,[ROOT] VARCHAR(50) ) CREATE TABLE #BIG_TABLE ( AN_ID INT ) go DECLARE @MAXDEPTH INT = 10 ;WITH cte_prepare AS ( SELECT ID ,ID_FATHER ,TB.X ,OT.[ROOT] FROM #MY_TABLE T LEFT …
If you want to have universal method you”ll need an additional class: public class TreeItem<T> { public T Item { get; set; } public IEnumerable<TreeItem<T>> Children { get; set; } } Then use it with this helper: internal static class GenericHelpers { /// <summary> /// Generates tree of items from item list /// </summary> /// …
Few thoughts on this: I would try modelling your Neo4j domain model to include the attributes of each node in the graph. By separating your data into two different data stores you might limit some operations that you might want to do. I guess it comes down to what you will be doing with your …
one option if you don’t want to travel down the hierarchical data-set path, is to use a Nested Set (http://en.wikipedia.org/wiki/Nested_set_model). this allows you to store the entire collection in a single array (or list or whatever you want to call it) and use a “left” and “right” value to determine the structure and hierarchy of …
Yes, this is possible, it’s a called a Modified Preorder Tree Traversal, as best described here Joe Celko’s Trees and Hierarchies in SQL for Smarties A working example (in PHP) is provided here http://www.sitepoint.com/article/hierarchical-data-database/2/
I’ve bookmarked this slidshare about SQL-Antipatterns, which discusses several alternatives: http://www.slideshare.net/billkarwin/sql-antipatterns-strike-back?src=embed The recommendation from there is to use a Closure Table (it’s explained in the slides). Here is the summary (slide 77): | Query Child | Query Subtree | Modify Tree | Ref. Integrity Adjacency List | Easy | Hard | Easy | Yes Path …
MongoDB and CouchDB offer solutions, but not built in functionality. See this SO question on representing hierarchy in a relational database as most other NoSQL solutions I’ve seen are similar in this regard; where you have to write your own algorithms for recalculating that information as nodes are added, deleted and moved. Generally speaking you’re …