Question

How can I set parent-child relation on same table?

Id int,  title string,  ParentId int  ---> this is refer to Id 

Answer 1

What ActiveRecord implementation are you using?

In Castle ActiveRecord, if your table looked like this:

table Document (    Id int primary key,    ParentDocumentId int,    Title string ) 

you’d use the following syntax:

[ActiveRecord(Table = 'Document')] public class Document : ActiveRecordBase<Document> {      private int id;     private Document parent;     private string title;     private List<Document> children = new List<Document>();      [PrimaryKey]     public int Id {         get { return id; }         set { id = value; }      }      [BelongsTo('ParentDocumentId')]     public virtual Document Parent {         get { return parent; }         set { parent = value; }     }      [HasMany(Table = 'Document', ColumnKey = 'ParentDocumentId', Inverse = true, Cascade = ManyRelationCascadeEnum.All)]     public IList<Document> Children {         get { return children.AsReadOnly(); }         private set { children = new List<Document>(value); }     }      [Property]     public string Title {         get { return title; }         set { title = value; }     } }