AssociationSetMetadata.cs source code in C# .NET

                        Code:
                         / Dotnetfx_Vista_SP2 / Dotnetfx_Vista_SP2 / 8.0.50727.4016 / DEVDIV / depot / DevDiv / releases / Orcas / QFE / ndp / fx / src / DataEntity / System / Data / Map / Update / Internal / AssociationSetMetadata.cs / 1 / AssociationSetMetadata.cs
                        
                        
                            //---------------------------------------------------------------------- 
// 
//      Copyright (c) Microsoft Corporation.  All rights reserved.
// 
// 
// @owner [....]
// @backupOwner [....] 
//--------------------------------------------------------------------- 

using System.Data.Metadata.Edm; 
using System.Data.Common.Utils;
using System.Data.Common.CommandTrees;
using System.Collections.Generic;
using System.Linq; 
namespace System.Data.Mapping.Update.Internal
{ 
    ///  
    /// Encapsulates information about ends of an association set needed to correctly
    /// interpret updates. 
    /// 
    internal class AssociationSetMetadata
    {
        ///  
        /// Gets association ends that must be modified if the association
        /// is changed (e.g. the mapping of the association is conditioned 
        /// on some property of the end) 
        /// 
        internal readonly Set RequiredEnds; 
        /// 
        /// Gets association ends that may be implicitly modified as a result
        /// of changes to the association (e.g. collocated entity with server
        /// generated value) 
        /// 
        internal readonly Set OptionalEnds; 
        ///  
        /// Gets association ends whose values may influence the association
        /// (e.g. where there is a ReferentialIntegrity or "common value" constraint) 
        /// 
        internal readonly Set IncludedValueEnds;
        /// 
        /// true iff. there are interesting ends for this association set. 
        /// 
        internal bool HasEnds 
        { 
            get { return 0 < RequiredEnds.Count || 0 < OptionalEnds.Count || 0 < IncludedValueEnds.Count; }
        } 

        /// 
        /// Initialize Metadata for an AssociationSet
        ///  
        internal AssociationSetMetadata(Set affectedTables, AssociationSet associationSet, MetadataWorkspace workspace)
        { 
            // If there is only 1 table, there can be no ambiguity about the "destination" of a relationship, so such 
            // sets are not typically required.
            bool isRequired = 1 < affectedTables.Count; 

            // determine the ends of the relationship
            var ends = associationSet.AssociationSetEnds;
 
            // find collocated entities
            foreach (EntitySet table in affectedTables) 
            { 
                // Find extents influencing the table
                DbQueryCommandTree updateMappingView = (DbQueryCommandTree)workspace.GetCqtView(table); 
                var influencingExtents = EntitySetRetriever.GetEntitySets(updateMappingView.Query);

                foreach (EntitySet influencingExtent in influencingExtents)
                { 
                    foreach (var end in ends)
                    { 
                        // If the extent is an end of the relationship and we haven't already added it to the 
                        // required set...
                        if (end.EntitySet.EdmEquals(influencingExtent)) 
                        {
                            if (isRequired)
                            {
                                AddEnd(ref RequiredEnds, end.CorrespondingAssociationEndMember); 
                            }
                            else if (null == RequiredEnds || !RequiredEnds.Contains(end.CorrespondingAssociationEndMember)) 
                            { 
                                AddEnd(ref OptionalEnds, end.CorrespondingAssociationEndMember);
                            } 
                        }
                    }
                }
            } 

            // fix Required and Optional sets 
            FixSet(ref RequiredEnds); 
            FixSet(ref OptionalEnds);
 
            // for associations with referential constraints, the principal end is always interesting
            // since its key values may take precedence over the key values of the dependent end
            foreach (ReferentialConstraint constraint in associationSet.ElementType.ReferentialConstraints)
            { 
                // FromRole is the principal end in the referential constraint
                AssociationEndMember principalEnd = (AssociationEndMember)constraint.FromRole; 
 
                if (!RequiredEnds.Contains(principalEnd) &&
                    !OptionalEnds.Contains(principalEnd)) 
                {
                    AddEnd(ref IncludedValueEnds, principalEnd);
                }
            } 

            FixSet(ref IncludedValueEnds); 
        } 

        ///  
        /// Initialize given required ends.
        /// 
        internal AssociationSetMetadata(IEnumerable requiredEnds)
        { 
            if (requiredEnds.Any())
            { 
                RequiredEnds = new Set(requiredEnds); 
            }
            FixSet(ref RequiredEnds); 
            FixSet(ref OptionalEnds);
            FixSet(ref IncludedValueEnds);
        }
 
        static private void AddEnd(ref Set set, AssociationEndMember element)
        { 
            if (null == set) 
            {
                set = new Set(); 
            }
            set.Add(element);
        }
 
        static private void FixSet(ref Set set)
        { 
            if (null == set) 
            {
                set = Set.Empty; 
            }
            else
            {
                set.MakeReadOnly(); 
            }
        } 
    } 
}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
//---------------------------------------------------------------------- 
// 
//      Copyright (c) Microsoft Corporation.  All rights reserved.
// 
// 
// @owner [....]
// @backupOwner [....] 
//--------------------------------------------------------------------- 

using System.Data.Metadata.Edm; 
using System.Data.Common.Utils;
using System.Data.Common.CommandTrees;
using System.Collections.Generic;
using System.Linq; 
namespace System.Data.Mapping.Update.Internal
{ 
    ///  
    /// Encapsulates information about ends of an association set needed to correctly
    /// interpret updates. 
    /// 
    internal class AssociationSetMetadata
    {
        ///  
        /// Gets association ends that must be modified if the association
        /// is changed (e.g. the mapping of the association is conditioned 
        /// on some property of the end) 
        /// 
        internal readonly Set RequiredEnds; 
        /// 
        /// Gets association ends that may be implicitly modified as a result
        /// of changes to the association (e.g. collocated entity with server
        /// generated value) 
        /// 
        internal readonly Set OptionalEnds; 
        ///  
        /// Gets association ends whose values may influence the association
        /// (e.g. where there is a ReferentialIntegrity or "common value" constraint) 
        /// 
        internal readonly Set IncludedValueEnds;
        /// 
        /// true iff. there are interesting ends for this association set. 
        /// 
        internal bool HasEnds 
        { 
            get { return 0 < RequiredEnds.Count || 0 < OptionalEnds.Count || 0 < IncludedValueEnds.Count; }
        } 

        /// 
        /// Initialize Metadata for an AssociationSet
        ///  
        internal AssociationSetMetadata(Set affectedTables, AssociationSet associationSet, MetadataWorkspace workspace)
        { 
            // If there is only 1 table, there can be no ambiguity about the "destination" of a relationship, so such 
            // sets are not typically required.
            bool isRequired = 1 < affectedTables.Count; 

            // determine the ends of the relationship
            var ends = associationSet.AssociationSetEnds;
 
            // find collocated entities
            foreach (EntitySet table in affectedTables) 
            { 
                // Find extents influencing the table
                DbQueryCommandTree updateMappingView = (DbQueryCommandTree)workspace.GetCqtView(table); 
                var influencingExtents = EntitySetRetriever.GetEntitySets(updateMappingView.Query);

                foreach (EntitySet influencingExtent in influencingExtents)
                { 
                    foreach (var end in ends)
                    { 
                        // If the extent is an end of the relationship and we haven't already added it to the 
                        // required set...
                        if (end.EntitySet.EdmEquals(influencingExtent)) 
                        {
                            if (isRequired)
                            {
                                AddEnd(ref RequiredEnds, end.CorrespondingAssociationEndMember); 
                            }
                            else if (null == RequiredEnds || !RequiredEnds.Contains(end.CorrespondingAssociationEndMember)) 
                            { 
                                AddEnd(ref OptionalEnds, end.CorrespondingAssociationEndMember);
                            } 
                        }
                    }
                }
            } 

            // fix Required and Optional sets 
            FixSet(ref RequiredEnds); 
            FixSet(ref OptionalEnds);
 
            // for associations with referential constraints, the principal end is always interesting
            // since its key values may take precedence over the key values of the dependent end
            foreach (ReferentialConstraint constraint in associationSet.ElementType.ReferentialConstraints)
            { 
                // FromRole is the principal end in the referential constraint
                AssociationEndMember principalEnd = (AssociationEndMember)constraint.FromRole; 
 
                if (!RequiredEnds.Contains(principalEnd) &&
                    !OptionalEnds.Contains(principalEnd)) 
                {
                    AddEnd(ref IncludedValueEnds, principalEnd);
                }
            } 

            FixSet(ref IncludedValueEnds); 
        } 

        ///  
        /// Initialize given required ends.
        /// 
        internal AssociationSetMetadata(IEnumerable requiredEnds)
        { 
            if (requiredEnds.Any())
            { 
                RequiredEnds = new Set(requiredEnds); 
            }
            FixSet(ref RequiredEnds); 
            FixSet(ref OptionalEnds);
            FixSet(ref IncludedValueEnds);
        }
 
        static private void AddEnd(ref Set set, AssociationEndMember element)
        { 
            if (null == set) 
            {
                set = new Set(); 
            }
            set.Add(element);
        }
 
        static private void FixSet(ref Set set)
        { 
            if (null == set) 
            {
                set = Set.Empty; 
            }
            else
            {
                set.MakeReadOnly(); 
            }
        } 
    } 
}

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

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