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//---------------------------------------------------------------------
// <copyright file="Metadata.cs" company="Microsoft">
// Copyright (c) Microsoft Corporation. All rights reserved.
// </copyright>
//
// @owner Microsoft
// @backupOwner Microsoft
//---------------------------------------------------------------------
using System;
using System.Collections.Generic;
using System.Data.Common;
using System.Data.Metadata.Edm;
using System.Globalization;
using System.Diagnostics;
namespace System.Data.Query.InternalTrees
{
/// <summary>
/// Describes metadata about a table
/// </summary>
internal class TableMD
{
private List<ColumnMD> m_columns;
private List<ColumnMD> m_keys;
private EntitySetBase m_extent; // null for transient tables
private bool m_flattened;
/// <summary>
/// private initializer
/// </summary>
/// <param name="extent">the entity set corresponding to this table (if any)</param>
private TableMD(EntitySetBase extent)
{
m_columns = new List<ColumnMD>();
m_keys = new List<ColumnMD>();
m_extent = extent;
}
/// <summary>
/// Create a typed-table definition corresponding to an entityset (if specified)
///
/// The table has exactly one column - the type of the column is specified by
/// the "type" parameter. This table is considered to be un-"flattened"
/// </summary>
/// <param name="type">type of each element (row) of the table</param>
/// <param name="extent">entityset corresponding to the table (if any)</param>
internal TableMD(TypeUsage type, EntitySetBase extent)
: this(extent)
{
m_columns.Add(new ColumnMD(this, "element", type));
m_flattened = !PlanCompiler.TypeUtils.IsStructuredType(type);
}
/// <summary>
/// Creates a "flattened" table definition.
///
/// The table has one column for each specified property in the "properties" parameter.
/// The name and datatype of each table column are taken from the corresponding property.
///
/// The keys of the table (if any) are those specified in the "keyProperties" parameter
///
/// The table may correspond to an entity set (if the entityset parameter was non-null)
/// </summary>
/// <param name="properties">prperties corresponding to columns of the table</param>
/// <param name="keyProperties"></param>
/// <param name="extent">entityset corresponding to the table (if any)</param>
internal TableMD(IEnumerable<EdmProperty> properties, IEnumerable<EdmMember> keyProperties,
EntitySetBase extent)
: this(extent)
{
Dictionary<string, ColumnMD> columnMap = new Dictionary<string, ColumnMD>();
m_flattened = true;
foreach (EdmProperty p in properties)
{
ColumnMD newColumn = new ColumnMD(this, p);
m_columns.Add(newColumn);
columnMap[p.Name] = newColumn;
}
foreach (EdmMember p in keyProperties)
{
ColumnMD keyColumn;
if (!columnMap.TryGetValue(p.Name, out keyColumn))
{
Debug.Assert(false, "keyMember not in columns?");
}
else
{
m_keys.Add(keyColumn);
}
}
}
/// <summary>
/// The extent metadata (if any)
/// </summary>
internal EntitySetBase Extent { get { return m_extent; } }
/// <summary>
/// List of columns of this table
/// </summary>
internal List<ColumnMD> Columns { get { return m_columns; } }
/// <summary>
/// Keys for this table
/// </summary>
internal List<ColumnMD> Keys { get { return m_keys; } }
/// <summary>
/// Is this table a "flat" table?
/// </summary>
internal bool Flattened { get { return m_flattened; } }
/// <summary>
/// String form - for debugging
/// </summary>
/// <returns></returns>
public override string ToString()
{
return (m_extent != null ? m_extent.Name : "Transient");
}
}
/// <summary>
/// Describes information about each column
/// </summary>
internal class ColumnMD
{
private string m_name;
private TypeUsage m_type;
private EdmMember m_property;
/// <summary>
/// Default constructor
/// </summary>
/// <param name="table">Table containing this column</param>
/// <param name="name">Column name</param>
/// <param name="type">Datatype of the column</param>
internal ColumnMD(TableMD table, string name, TypeUsage type)
{
m_name = name;
m_type = type;
}
/// <summary>
/// More useful default constructor
/// </summary>
/// <param name="table">table containing this column</param>
/// <param name="property">property describing this column</param>
internal ColumnMD(TableMD table, EdmMember property)
: this(table, property.Name, property.TypeUsage)
{
m_property = property;
}
/// <summary>
/// Column Name
/// </summary>
internal string Name { get { return m_name; } }
/// <summary>
/// Datatype of the column
/// </summary>
internal TypeUsage Type { get { return m_type; } }
/// <summary>
/// Is this column nullable ?
/// </summary>
internal bool IsNullable
{
get
{
return (m_property == null) || TypeSemantics.IsNullable(m_property);
}
}
/// <summary>
/// debugging help
/// </summary>
/// <returns></returns>
public override string ToString()
{
return m_name;
}
}
/// <summary>
/// Represents one instance of a table. Contains the table metadata
/// </summary>
internal class Table
{
private TableMD m_tableMetadata;
private VarList m_columns;
private VarVec m_referencedColumns;
private VarVec m_keys;
private VarVec m_nonnullableColumns;
private int m_tableId;
internal Table(Command command, TableMD tableMetadata, int tableId)
{
m_tableMetadata = tableMetadata;
m_columns = Command.CreateVarList();
m_keys = command.CreateVarVec();
m_nonnullableColumns = command.CreateVarVec();
m_tableId = tableId;
Dictionary<string, ColumnVar> columnVarMap = new Dictionary<string, ColumnVar>();
foreach (ColumnMD c in tableMetadata.Columns)
{
ColumnVar v = command.CreateColumnVar(this, c);
columnVarMap[c.Name] = v;
if (!c.IsNullable)
{
m_nonnullableColumns.Set(v);
}
}
foreach (ColumnMD c in tableMetadata.Keys)
{
ColumnVar v = columnVarMap[c.Name];
m_keys.Set(v);
}
m_referencedColumns = command.CreateVarVec(m_columns);
}
/// <summary>
/// Metadata for the table instance
/// </summary>
internal TableMD TableMetadata { get { return m_tableMetadata; } }
/// <summary>
/// List of column references
/// </summary>
internal VarList Columns { get { return m_columns; } }
/// <summary>
/// Get the list of all referenced columns.
/// </summary>
internal VarVec ReferencedColumns
{
get { return m_referencedColumns; }
}
/// <summary>
///
/// </summary>
internal VarVec NonNullableColumns { get { return m_nonnullableColumns; } }
/// <summary>
/// List of keys
/// </summary>
internal VarVec Keys { get { return m_keys; } }
/// <summary>
/// (internal) id for this table instance
/// </summary>
internal int TableId { get { return m_tableId; } }
/// <summary>
/// String form - for debugging
/// </summary>
/// <returns></returns>
public override string ToString()
{
return String.Format(CultureInfo.InvariantCulture, "{0}::{1}", m_tableMetadata.ToString(), this.TableId); ;
}
}
}
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