102 lines
3.4 KiB
C#
102 lines
3.4 KiB
C#
//---------------------------------------------------------------------
|
|
// <copyright file="JoinSymbol.cs" company="Microsoft">
|
|
// Copyright (c) Microsoft Corporation. All rights reserved.
|
|
// </copyright>
|
|
//
|
|
// @owner [....]
|
|
// @backupOwner [....]
|
|
//---------------------------------------------------------------------
|
|
|
|
using System;
|
|
using System.Collections.Generic;
|
|
using System.Diagnostics;
|
|
using System.IO;
|
|
using System.Text;
|
|
using System.Data.SqlClient;
|
|
using System.Data.Metadata.Edm;
|
|
using System.Data.Common.CommandTrees;
|
|
|
|
namespace System.Data.SqlClient.SqlGen
|
|
{
|
|
/// <summary>
|
|
/// A Join symbol is a special kind of Symbol.
|
|
/// It has to carry additional information
|
|
/// <list type="bullet">
|
|
/// <item>ColumnList for the list of columns in the select clause if this
|
|
/// symbol represents a sql select statement. This is set by <see cref="SqlGenerator.AddDefaultColumns"/>. </item>
|
|
/// <item>ExtentList is the list of extents in the select clause.</item>
|
|
/// <item>FlattenedExtentList - if the Join has multiple extents flattened at the
|
|
/// top level, we need this information to ensure that extent aliases are renamed
|
|
/// correctly in <see cref="SqlSelectStatement.WriteSql"/></item>
|
|
/// <item>NameToExtent has all the extents in ExtentList as a dictionary.
|
|
/// This is used by <see cref="SqlGenerator.Visit(DbPropertyExpression)"/> to flatten
|
|
/// record accesses.</item>
|
|
/// <item>IsNestedJoin - is used to determine whether a JoinSymbol is an
|
|
/// ordinary join symbol, or one that has a corresponding SqlSelectStatement.</item>
|
|
/// </list>
|
|
///
|
|
/// All the lists are set exactly once, and then used for lookups/enumerated.
|
|
/// </summary>
|
|
internal sealed class JoinSymbol : Symbol
|
|
{
|
|
private List<Symbol> columnList;
|
|
internal List<Symbol> ColumnList
|
|
{
|
|
get
|
|
{
|
|
if (null == columnList)
|
|
{
|
|
columnList = new List<Symbol>();
|
|
}
|
|
return columnList;
|
|
}
|
|
set { columnList = value; }
|
|
}
|
|
|
|
private List<Symbol> extentList;
|
|
internal List<Symbol> ExtentList
|
|
{
|
|
get { return extentList; }
|
|
}
|
|
|
|
private List<Symbol> flattenedExtentList;
|
|
internal List<Symbol> FlattenedExtentList
|
|
{
|
|
get
|
|
{
|
|
if (null == flattenedExtentList)
|
|
{
|
|
flattenedExtentList = new List<Symbol>();
|
|
}
|
|
return flattenedExtentList;
|
|
}
|
|
set { flattenedExtentList = value; }
|
|
}
|
|
|
|
private Dictionary<string, Symbol> nameToExtent;
|
|
internal Dictionary<string, Symbol> NameToExtent
|
|
{
|
|
get { return nameToExtent; }
|
|
}
|
|
|
|
private bool isNestedJoin;
|
|
internal bool IsNestedJoin
|
|
{
|
|
get { return isNestedJoin; }
|
|
set { isNestedJoin = value; }
|
|
}
|
|
|
|
public JoinSymbol(string name, TypeUsage type, List<Symbol> extents)
|
|
: base(name, type)
|
|
{
|
|
extentList = new List<Symbol>(extents.Count);
|
|
nameToExtent = new Dictionary<string, Symbol>(extents.Count, StringComparer.OrdinalIgnoreCase);
|
|
foreach (Symbol symbol in extents)
|
|
{
|
|
this.nameToExtent[symbol.Name] = symbol;
|
|
this.ExtentList.Add(symbol);
|
|
}
|
|
}
|
|
}
|
|
}
|