DbUpdateCommandTree.cs source code in C# .NET

Source code for the .NET framework in C#

                        
Code:

                         / 4.0 / 4.0 / untmp / DEVDIV_TFS / Dev10 / Releases / RTMRel / ndp / fx / src / DataEntity / System / Data / Common / CommandTrees / DbUpdateCommandTree.cs / 1305376 / DbUpdateCommandTree.cs
                        

                        
                            //---------------------------------------------------------------------- 
// 
//      Copyright (c) Microsoft Corporation.  All rights reserved.
// 
// 
// @owner  [....], [....]
// @backupOwner [....] 
//--------------------------------------------------------------------- 

using System; 
using System.Collections.Generic;

using System.Data.Metadata.Edm;
using System.Data.Common.CommandTrees.Internal; 
using System.Data.Common.Utils;
using System.Diagnostics; 
 
using ReadOnlyModificationClauses = System.Collections.ObjectModel.ReadOnlyCollection;  // System.Data.Common.ReadOnlyCollection conflicts
 
namespace System.Data.Common.CommandTrees
{
    /// 
    /// Represents a single-row update operation expressed as a canonical command tree. 
    /// When the  property is set, the command returns a reader; otherwise,
    /// it returns a scalar indicating the number of rows affected. 
    ///  
    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Naming", "CA1709:IdentifiersShouldBeCasedCorrectly", MessageId = "Db")]
    public sealed class DbUpdateCommandTree : DbModificationCommandTree 
    {
        private readonly DbExpression _predicate;
        private readonly DbExpression _returning;
        private readonly ReadOnlyModificationClauses _setClauses; 

        internal DbUpdateCommandTree(MetadataWorkspace metadata, DataSpace dataSpace, DbExpressionBinding target, DbExpression predicate, ReadOnlyModificationClauses setClauses, DbExpression returning) 
            : base(metadata, dataSpace, target) 
        {
            EntityUtil.CheckArgumentNull(predicate, "predicate"); 
            EntityUtil.CheckArgumentNull(setClauses, "setClauses");
            // returning is allowed to be null

            this._predicate = predicate; 
            this._setClauses = setClauses;
            this._returning = returning; 
        } 

        ///  
        /// Gets the list of update set clauses that define the update operation.
        /// 
        public IList SetClauses
        { 
            get
            { 
                return _setClauses; 
            }
        } 

        /// 
        /// Gets an  that specifies a projection of results to be returned based on the modified rows.
        /// If null, indicates no results should be returned from this command. 
        /// 
        ///  
        /// The returning projection includes only the following elements: 
        /// 
        /// NewInstance expression 
        /// Property expression
        /// 
        /// 
        public DbExpression Returning 
        {
            get 
            { 
                return _returning;
            } 
        }

        /// 
        /// Gets an  that specifies the predicate used to determine which members of the target collection should be updated. 
        /// 
        ///  
        /// The predicate includes only the following elements: 
        /// 
        /// Equality expression 
        /// Constant expression
        /// IsNull expression
        /// Property expression
        /// Reference expression to the target 
        /// And expression
        /// Or expression 
        /// Not expression 
        /// 
        ///  
        public DbExpression Predicate
        {
            get
            { 
                return _predicate;
            } 
        } 

        internal override DbCommandTreeKind CommandTreeKind 
        {
            get { return DbCommandTreeKind.Update; }
        }
 
        internal override bool HasReader
        { 
            get { return null != Returning; } 
        }
 
        internal override void DumpStructure(ExpressionDumper dumper)
        {
            base.DumpStructure(dumper);
 
            if (this.Predicate != null)
            { 
                dumper.Dump(this.Predicate, "Predicate"); 
            }
 
            dumper.Begin("SetClauses", null);
            foreach (DbModificationClause clause in this.SetClauses)
            {
                if (null != clause) 
                {
                    clause.DumpStructure(dumper); 
                } 
            }
            dumper.End("SetClauses"); 

            dumper.Dump(this.Returning, "Returning");
        }
 
        internal override string PrintTree(ExpressionPrinter printer)
        { 
            return printer.Print(this); 
        }
    } 
}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.

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