DbQueryCommandTree.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 / DbQueryCommandTree.cs / 1305376 / DbQueryCommandTree.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.Linq; 
using System.Diagnostics; 

namespace System.Data.Common.CommandTrees 
{
    /// 
    /// Represents a query operation expressed as a canonical command tree.
    ///  
    [System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Naming", "CA1709:IdentifiersShouldBeCasedCorrectly", MessageId = "Db")]
    public sealed class DbQueryCommandTree : DbCommandTree 
    { 
        // Query expression
        private readonly DbExpression _query; 

        // Parameter information (will be retrieved from the components of the command tree before construction)
        private System.Collections.ObjectModel.ReadOnlyCollection _parameters;
 
        private DbQueryCommandTree(MetadataWorkspace metadata,
                                   DataSpace dataSpace, 
                                   DbExpression query, 
                                   bool validate)
            : base(metadata, dataSpace) 
        {
            // Ensure the query expression is non-null
            EntityUtil.CheckArgumentNull(query, "query");
 
            using (new EntityBid.ScopeAuto(" %d#, query=%d#", this.ObjectId, query.ObjectId))
            { 
                if (validate) 
                {
                    // Use the valid workspace and data space to validate the query expression 
                    DbExpressionValidator validator = new DbExpressionValidator(metadata, dataSpace);
                    validator.ValidateExpression(query, "query");

                    this._parameters = validator.Parameters.Select(paramInfo => paramInfo.Value).ToList().AsReadOnly(); 
                }
                this._query = query; 
            } 
        }
 
        /// 
        /// Constructs a new DbQueryCommandTree that uses the specified metadata workspace.
        /// 
        /// The metadata workspace that the command tree should use. 
        /// The logical 'space' that metadata in the expressions used in this command tree must belong to.
        /// A  that defines the logic of the query. 
        ///  or  is null 
        ///  does not represent a valid data space
        /*CQT_PUBLIC_API(*/internal/*)*/ DbQueryCommandTree(MetadataWorkspace metadata, DataSpace dataSpace, DbExpression query) 
            : this(metadata, dataSpace, query, true)
        {

        } 

        ///  
        /// Gets a  that defines the logic of the query. 
        /// 
        public DbExpression Query 
        {
            get { return this._query; }
        }
 
        internal override DbCommandTreeKind CommandTreeKind
        { 
            get { return DbCommandTreeKind.Query; } 
        }
 
        internal override IEnumerable> GetParameters()
        {
            if (this._parameters == null)
            { 
                this._parameters = ParameterRetriever.GetParameters(this);
            } 
            return this._parameters.Select(p => new KeyValuePair(p.ParameterName, p.ResultType)); 
        }
 
        internal override void DumpStructure(ExpressionDumper dumper)
        {
            if (this.Query != null)
            { 
                dumper.Dump(this.Query, "Query");
            } 
        } 

        internal override string PrintTree(ExpressionPrinter printer) 
        {
            return printer.Print(this);
        }
 
        internal static DbQueryCommandTree FromValidExpression(MetadataWorkspace metadata, DataSpace dataSpace, DbExpression query)
        { 
#if DEBUG 
            return new DbQueryCommandTree(metadata, dataSpace, query);
#else 
            return new DbQueryCommandTree(metadata, dataSpace, query, false);
#endif
        }
    } 
}

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.

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