EntitySet.cs source code in C# .NET

                        Code:
                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / DataEntity / System / Data / Metadata / Edm / EntitySet.cs / 1305376 / EntitySet.cs
                        
                        
                            //---------------------------------------------------------------------- 
// 
//      Copyright (c) Microsoft Corporation.  All rights reserved.
// 
// 
// @owner       [....]
// @backupOwner [....] 
//--------------------------------------------------------------------- 

using System; 
using System.Collections.Generic;
using System.Text;
using System.Diagnostics;
using System.Threading; 
using System.Data.Common.Utils;
using System.Collections.ObjectModel; 
 
namespace System.Data.Metadata.Edm
{ 
    /// 
    /// concrete Class for representing a entity set
    /// 
    public class EntitySet : EntitySetBase 
    {
        #region Constructors 
        ///  
        /// The constructor for constructing the EntitySet with a given name and an entity type
        ///  
        /// The name of the EntitySet
        /// The db schema
        /// The db table
        /// The provider specific query that should be used to retrieve the EntitySet 
        /// The entity type of the entities that this entity set type contains
        /// Thrown if the argument name or entityType is null 
        internal EntitySet(string name, string schema, string table, string definingQuery, EntityType entityType) 
            : base(name, schema, table, definingQuery, entityType)
        { 
        }
        #endregion

        #region Fields 
        private ReadOnlyCollection> _foreignKeyDependents;
        private ReadOnlyCollection> _foreignKeyPrincipals; 
        private volatile bool _hasForeignKeyRelationships; 
        private volatile bool _hasIndependentRelationships;
        #endregion 

        #region Properties
        /// 
        /// Returns the kind of the type 
        /// 
        public override BuiltInTypeKind BuiltInTypeKind { get { return BuiltInTypeKind.EntitySet; } } 
 
        /// 
        /// Gets/Sets the entity type of this entity set 
        /// 
        public new EntityType ElementType
        {
            get 
            {
                return (EntityType)base.ElementType; 
            } 
        }
 
        /// 
        /// Returns the associations and constraints where "this" EntitySet particpates as the Principal end.
        /// From the results of this list, you can retrieve the Dependent IRelatedEnds
        ///  
        internal ReadOnlyCollection> ForeignKeyDependents
        { 
            get 
            {
                if (_foreignKeyDependents == null) 
                {
                    InitializeForeignKeyLists();
                }
                return _foreignKeyDependents; 
            }
        } 
 
        /// 
        /// Returns the associations and constraints where "this" EntitySet particpates as the Dependent end. 
        /// From the results of this list, you can retrieve the Principal IRelatedEnds
        /// 
        internal ReadOnlyCollection> ForeignKeyPrincipals
        { 
            get
            { 
                if (_foreignKeyPrincipals == null) 
                {
                    InitializeForeignKeyLists(); 
                }
                return _foreignKeyPrincipals;
            }
        } 

        ///  
        /// True if this entity set participates in any foreign key relationships, otherwise false. 
        /// 
        internal bool HasForeignKeyRelationships 
        {
            get
            {
                if (_foreignKeyPrincipals == null) 
                {
                    InitializeForeignKeyLists(); 
                } 
                return _hasForeignKeyRelationships;
            } 
        }

        /// 
        /// True if this entity set participates in any independent relationships, otherwise false. 
        /// 
        internal bool HasIndependentRelationships 
        { 
            get
            { 
                if (_foreignKeyPrincipals == null)
                {
                    InitializeForeignKeyLists();
                } 
                return _hasIndependentRelationships;
            } 
        } 

        #endregion 

        #region Methods
        private void InitializeForeignKeyLists()
        { 
            var dependents = new List>();
            var principals = new List>(); 
            bool foundFkRelationship = false; 
            bool foundIndependentRelationship = false;
            foreach (AssociationSet associationSet in MetadataHelper.GetAssociationsForEntitySet(this)) 
            {
                if (associationSet.ElementType.IsForeignKey)
                {
                    foundFkRelationship = true; 
                    Debug.Assert(associationSet.ElementType.ReferentialConstraints.Count == 1, "Expected exactly one constraint for FK");
                    ReferentialConstraint constraint = associationSet.ElementType.ReferentialConstraints[0]; 
                    if (constraint.ToRole.GetEntityType().IsAssignableFrom(this.ElementType) || 
                        this.ElementType.IsAssignableFrom(constraint.ToRole.GetEntityType()))
                    { 
                        // Dependents
                        dependents.Add(new Tuple(associationSet, constraint));
                    }
                    if (constraint.FromRole.GetEntityType().IsAssignableFrom(this.ElementType) || 
                        this.ElementType.IsAssignableFrom(constraint.FromRole.GetEntityType()))
                    { 
                        // Principals 
                        principals.Add(new Tuple(associationSet, constraint));
                    } 
                }
                else
                {
                    foundIndependentRelationship = true; 
                }
            } 
 
            _hasForeignKeyRelationships = foundFkRelationship;
            _hasIndependentRelationships = foundIndependentRelationship; 

            var readOnlyDependents = dependents.AsReadOnly();
            var readOnlyPrincipals = principals.AsReadOnly();
 
            Interlocked.CompareExchange(ref _foreignKeyDependents, readOnlyDependents, null);
            Interlocked.CompareExchange(ref _foreignKeyPrincipals, readOnlyPrincipals, null); 
        } 
        #endregion
    } 
}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
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EntitySet.cs source code in C# .NET

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