C#3.0入门系列（LinQ）（七）-之OR工具介绍

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C# 3.0 LinQ

Linq C#C++C SQL Server

不得不再次给关注 dlinq的朋友道歉了。好久都没有更新 blog了。因为工作的变动，还要赶期限，没有时间关注这里了。

先发布一则消息。 Orcas Beta1，这个才是 beta1，可以到 http://www.microsoft.com/downloads/details.aspx?FamilyID=f10fb5df-e369-4db4-b9a7-845dbf793368&DisplayLang=en 下载。 5月 1号的版本。最早 4月 19号就出来过一个，只是没有在意。还有一个 http://www.microsoft.com/downloads/details.aspx?FamilyID=36b6609e-6f3d-40f4-8c7d-ad111679d8dc&DisplayLang=en

http://www.my400800.cn 。一个是 self-extracting 版本的，一个是 Virtual PC version的。不知道什么区别。没有装过。

本节舍去原来的计划，而改讲映射工具。在入门三一文中，我们提到了 sqlmetal这个工具。 http://www.cnblogs.com/126/archive/2006/09/06/492332.html sqlmetal的功能是将数据库的信息抽提出来，生成映射代码。 Orcas还有另外一个工具，就是 O/R Designer.

先讲 sqlmetal. 自上次的版本后， sqlmetal，又增加了一些新的功能。比如，支持 SQLCE版本的 Sql Server, 支持直接输入 connection string，等等。这是 sqlmetal的帮助信息，是不是比上次多了很多？

Microsoft (R) Database Mapping Generator 2008 Beta 2 version 1.00.20612
for Microsoft (R) .NET Framework version 3.5
Copyright (C) Microsoft Corporation. All rights reserved.

SqlMetal [options] [<input file>]

  Generates code and mapping for the LINQ to SQL component of the .NET framework. SqlMetal can:
  - Generate source code and mapping attributes or a mapping file from a database.
  - Generate an intermediate dbml file for customization from the database.
  - Generate code and mapping attributes or mapping file from a dbml file.

Options:
  /server:<name>             Database server name.
  /database:<name>           Database catalog on server.
  /user:<name>               Login user ID (default: use Windows Authentication).
  /password:<password>       Login password (default: use Windows Authentication).
  /conn:<connection string>  Database connection string. Cannot be used with /server, /database, /us
er or /password options.
  /timeout:<seconds>         Timeout value to use when SqlMetal accesses the database (default: 0 wh
ich means infinite).

  /views                     Extract database views.
  /functions                 Extract database functions.
  /sprocs                    Extract stored procedures.

  /dbml[:file]               Output as dbml. Cannot be used with /map option.
  /code[:file]               Output as source code. Cannot be used with /dbml option.
  /map[:file]                Generate mapping file, not attributes. Cannot be used with /dbml option
.

  /language:<language>       Language for source code: VB or C# (default: derived from extension on code file name).
  /namespace:<name>          Namespace of generated code (default: no namespace).
  /context:<type>            Name of data context class (default: derived from database name).
  /entitybase:<type>         Base class of entity classes in the generated code (default: entities have no base class).
  /pluralize                 Automatically pluralize or singularize class and member names using English language rules.
  /serialization:<option>    Generate serializable classes: None or Unidirectional (default: None).
  /provider:<type>           Provider type (default: provider is determined at run time).

  <input file>               May be a SqlExpress mdf file, a SqlCE sdf file, or a dbml intermediate file.

Create code from SqlServer:
  SqlMetal /server:myserver /database:northwind /code:nwind.cs /namespace:nwind

Generate intermediate dbml file from SqlServer:
  SqlMetal /server:myserver /database:northwind /dbml:northwind.dbml /namespace:nwind

Generate code with external mapping from dbml:
  SqlMetal /code:nwind.cs /map:nwind.map northwind.dbml

Generate dbml from a SqlCE sdf file:
  SqlMetal /dbml:northwind.dbml northwind.sdf

Generate dbml from SqlExpress local server:
  SqlMetal /server:.\sqlexpress /database:northwind /dbml:northwind.dbml

Generate dbml by using a connection string in the command line:
  SqlMetal /conn:"server='myserver'; database='northwind'" /dbml:northwind.dbml

因为 sqlmetal已经讲过，不再多讲，大家知道它是个命令行的工具，用来做映射数据库信息的，会使用就可以。再接着讲 O/R Designer. 新建任一工程。右击工程，选择 add->new item. 如图所示：

弹出 item 对话框， category 中选择 data, 然后选择 Linq to Sql Class ，如图所示：

选择添加。这样，你的工程就多了一个 O/R Desiger项目。在菜单 View->Sever Explore 打开 Sever Explore，添加一个 Data Connection, 如图所示：

后，填写数据库服务器，用户名，密码和数据库名。如果，你没有，你可以使用 Sql Express 版本。添加之后的效果，如图所示：

打开刚才添加的 DataClasses1.dbml 文件，将 Sever Explore中的 Customer 表或 view拖入 Designer中来，如图所示：

也可以将 Store procedure 和 User define function 拖进来，会在方法面板上形成方法。如图所示：

如果，两个表之间有关系， OR Designer可以显示它们的关系，将 Order表和 OderDetail表拖入如图所示：

打开 DataClasses1. Designer.cs 文件，你就可以看到 OR Designer 给你产生的映射代码了。

using System.Data.Linq;
    using System.Data.Linq.Mapping;
    using System.Data;
    using System.Collections.Generic;
    using System.Reflection;
    using System.Linq;
    using System.Linq.Expressions;
    using System.ComponentModel;
    using System;
    
    
    [System.Data.Linq.Mapping.DatabaseAttribute(Name="northwind_may06ctp")]
    public partial class DataClasses1DataContext : System.Data.Linq.DataContext
    {
        
        private static System.Data.Linq.Mapping.MappingSource mappingSource = new AttributeMappingSource();
        
    Extensibility Method Definitions#region Extensibility Method Definitions
    partial void OnCreated();
    partial void InsertOrder(Order instance);
    partial void UpdateOrder(Order instance);
    partial void DeleteOrder(Order instance);
    partial void InsertOrder_Detail(Order_Detail instance);
    partial void UpdateOrder_Detail(Order_Detail instance);
    partial void DeleteOrder_Detail(Order_Detail instance);
    #endregion
        
        static DataClasses1DataContext()
        {
        }
        
        public DataClasses1DataContext(string connection) : 
                base(connection, mappingSource)
        {
            OnCreated();
        }
        
        public DataClasses1DataContext(System.Data.IDbConnection connection) : 
                base(connection, mappingSource)
        {
            OnCreated();
        }
        
        public DataClasses1DataContext(string connection, System.Data.Linq.Mapping.MappingSource mappingSource) : 
                base(connection, mappingSource)
        {
            OnCreated();
        }
        
        public DataClasses1DataContext(System.Data.IDbConnection connection, System.Data.Linq.Mapping.MappingSource mappingSource) : 
                base(connection, mappingSource)
        {
            OnCreated();
        }
        
        public DataClasses1DataContext() : 
                base(global::SqlMetalUtil.Properties.Settings.Default.northwind_may06ctpConnectionString, mappingSource)
        {
            OnCreated();
        }
        
        public System.Data.Linq.Table<Order> Orders
        {
            get
            {
                return this.GetTable<Order>();
            }
        }
        
        public System.Data.Linq.Table<Order_Detail> Order_Details
        {
            get
            {
                return this.GetTable<Order_Detail>();
            }
        }
        
        [Function(Name="dbo.CategoriesInsert")]
        public int CategoriesInsert([Parameter(Name="@CategoryID", DbType="int")] System.Nullable<int> CategoryID, [Parameter(Name="@CategoryName", DbType="nvarchar")] string CategoryName, [Parameter(Name="@Description", DbType="ntext")] string Description, [Parameter(Name="@Picture", DbType="image")] byte[] Picture)
        {
            IExecuteResult result = this.ExecuteMethodCall(this, ((MethodInfo)(MethodInfo.GetCurrentMethod())), CategoryID, CategoryName, Description, Picture);
            return ((int)(result.ReturnValue));
        }
    }
    
    [Table(Name="dbo.Orders")]
    public partial class Order : INotifyPropertyChanging, INotifyPropertyChanged
    {
        
        private static PropertyChangingEventArgs emptyChangingEventArgs = new PropertyChangingEventArgs(String.Empty);
        
        private int _OrderID;
        
        private string _CustomerID;
        
        private System.Nullable<int> _EmployeeID;
        
        private System.Nullable<System.DateTime> _OrderDate;
        
        private System.Nullable<System.DateTime> _RequiredDate;
        
        private System.Nullable<System.DateTime> _ShippedDate;
        
        private System.Nullable<int> _ShipVia;
        
        private System.Nullable<decimal> _Freight;
        
        private string _ShipName;
        
        private string _ShipAddress;
        
        private string _ShipCity;
        
        private string _ShipRegion;
        
        private string _ShipPostalCode;
        
        private string _ShipCountry;
        
        private EntitySet<Order_Detail> _Order_Details;
        
    Extensibility Method Definitions#region Extensibility Method Definitions
    partial void OnLoaded();
    partial void OnValidate();
    partial void OnCreated();
    partial void OnOrderIDChanging(int value);
    partial void OnOrderIDChanged();
    partial void OnCustomerIDChanging(string value);
    partial void OnCustomerIDChanged();
    partial void OnEmployeeIDChanging(System.Nullable<int> value);
    partial void OnEmployeeIDChanged();
    partial void OnOrderDateChanging(System.Nullable<System.DateTime> value);
    partial void OnOrderDateChanged();
    partial void OnRequiredDateChanging(System.Nullable<System.DateTime> value);
    partial void OnRequiredDateChanged();
    partial void OnShippedDateChanging(System.Nullable<System.DateTime> value);
    partial void OnShippedDateChanged();
    partial void OnShipViaChanging(System.Nullable<int> value);
    partial void OnShipViaChanged();
    partial void OnFreightChanging(System.Nullable<decimal> value);
    partial void OnFreightChanged();
    partial void OnShipNameChanging(string value);
    partial void OnShipNameChanged();
    partial void OnShipAddressChanging(string value);
    partial void OnShipAddressChanged();
    partial void OnShipCityChanging(string value);
    partial void OnShipCityChanged();
    partial void OnShipRegionChanging(string value);
    partial void OnShipRegionChanged();
    partial void OnShipPostalCodeChanging(string value);
    partial void OnShipPostalCodeChanged();
    partial void OnShipCountryChanging(string value);
    partial void OnShipCountryChanged();
    #endregion
        
        public Order()
        {
            OnCreated();
            this._Order_Details = new EntitySet<Order_Detail>(new Action<Order_Detail>(this.attach_Order_Details), new Action<Order_Detail>(this.detach_Order_Details));
        }
        
        [Column(Storage="_OrderID", AutoSync=AutoSync.OnInsert, DbType="Int NOT NULL IDENTITY", IsPrimaryKey=true, IsDbGenerated=true)]
        public int OrderID
        {
            get
            {
                return this._OrderID;
            }
            set
            {
                if ((this._OrderID != value))
                {
                    this.OnOrderIDChanging(value);
                    this.SendPropertyChanging();
                    this._OrderID = value;
                    this.SendPropertyChanged("OrderID");
                    this.OnOrderIDChanged();
                }
            }
        }
        
        [Column(Storage="_CustomerID", DbType="NChar(5)")]
        public string CustomerID
        {
            get
            {
                return this._CustomerID;
            }
            set
            {
                if ((this._CustomerID != value))
                {
                    this.OnCustomerIDChanging(value);
                    this.SendPropertyChanging();
                    this._CustomerID = value;
                    this.SendPropertyChanged("CustomerID");
                    this.OnCustomerIDChanged();
                }
            }
        }
        
        [Column(Storage="_EmployeeID", DbType="Int")]
        public System.Nullable<int> EmployeeID
        {
            get
            {
                return this._EmployeeID;
            }
            set
            {
                if ((this._EmployeeID != value))
                {
                    this.OnEmployeeIDChanging(value);
                    this.SendPropertyChanging();
                    this._EmployeeID = value;
                    this.SendPropertyChanged("EmployeeID");
                    this.OnEmployeeIDChanged();
                }
            }
        }
        
        [Column(Storage="_OrderDate", DbType="DateTime")]
        public System.Nullable<System.DateTime> OrderDate
        {
            get
            {
                return this._OrderDate;
            }
            set
            {
                if ((this._OrderDate != value))
                {
                    this.OnOrderDateChanging(value);
                    this.SendPropertyChanging();
                    this._OrderDate = value;
                    this.SendPropertyChanged("OrderDate");
                    this.OnOrderDateChanged();
                }
            }
        }
        
        [Column(Storage="_RequiredDate", DbType="DateTime")]
        public System.Nullable<System.DateTime> RequiredDate
        {
            get
            {
                return this._RequiredDate;
            }
            set
            {
                if ((this._RequiredDate != value))
                {
                    this.OnRequiredDateChanging(value);
                    this.SendPropertyChanging();
                    this._RequiredDate = value;
                    this.SendPropertyChanged("RequiredDate");
                    this.OnRequiredDateChanged();
                }
            }
        }
        
        [Column(Storage="_ShippedDate", DbType="DateTime")]
        public System.Nullable<System.DateTime> ShippedDate
        {
            get
            {
                return this._ShippedDate;
            }
            set
            {
                if ((this._ShippedDate != value))
                {
                    this.OnShippedDateChanging(value);
                    this.SendPropertyChanging();
                    this._ShippedDate = value;
                    this.SendPropertyChanged("ShippedDate");
                    this.OnShippedDateChanged();
                }
            }
        }
        
        [Column(Storage="_ShipVia", DbType="Int")]
        public System.Nullable<int> ShipVia
        {
            get
            {
                return this._ShipVia;
            }
            set
            {
                if ((this._ShipVia != value))
                {
                    this.OnShipViaChanging(value);
                    this.SendPropertyChanging();
                    this._ShipVia = value;
                    this.SendPropertyChanged("ShipVia");
                    this.OnShipViaChanged();
                }
            }
        }
        
        [Column(Storage="_Freight", DbType="Money")]
        public System.Nullable<decimal> Freight
        {
            get
            {
                return this._Freight;
            }
            set
            {
                if ((this._Freight != value))
                {
                    this.OnFreightChanging(value);
                    this.SendPropertyChanging();
                    this._Freight = value;
                    this.SendPropertyChanged("Freight");
                    this.OnFreightChanged();
                }
            }
        }
        
        [Column(Storage="_ShipName", DbType="NVarChar(40)")]
        public string ShipName
        {
            get
            {
                return this._ShipName;
            }
            set
            {
                if ((this._ShipName != value))
                {
                    this.OnShipNameChanging(value);
                    this.SendPropertyChanging();
                    this._ShipName = value;
                    this.SendPropertyChanged("ShipName");
                    this.OnShipNameChanged();
                }
            }
        }
        
        [Column(Storage="_ShipAddress", DbType="NVarChar(60)")]
        public string ShipAddress
        {
            get
            {
                return this._ShipAddress;
            }
            set
            {
                if ((this._ShipAddress != value))
                {
                    this.OnShipAddressChanging(value);
                    this.SendPropertyChanging();
                    this._ShipAddress = value;
                    this.SendPropertyChanged("ShipAddress");
                    this.OnShipAddressChanged();
                }
            }
        }
        
        [Column(Storage="_ShipCity", DbType="NVarChar(15)")]
        public string ShipCity
        {
            get
            {
                return this._ShipCity;
            }
            set
            {
                if ((this._ShipCity != value))
                {
                    this.OnShipCityChanging(value);
                    this.SendPropertyChanging();
                    this._ShipCity = value;
                    this.SendPropertyChanged("ShipCity");
                    this.OnShipCityChanged();
                }
            }
        }
        
        [Column(Storage="_ShipRegion", DbType="NVarChar(15)")]
        public string ShipRegion
        {
            get
            {
                return this._ShipRegion;
            }
            set
            {
                if ((this._ShipRegion != value))
                {
                    this.OnShipRegionChanging(value);
                    this.SendPropertyChanging();
                    this._ShipRegion = value;
                    this.SendPropertyChanged("ShipRegion");
                    this.OnShipRegionChanged();
                }
            }
        }
        
        [Column(Storage="_ShipPostalCode", DbType="NVarChar(10)")]
        public string ShipPostalCode
        {
            get
            {
                return this._ShipPostalCode;
            }
            set
            {
                if ((this._ShipPostalCode != value))
                {
                    this.OnShipPostalCodeChanging(value);
                    this.SendPropertyChanging();
                    this._ShipPostalCode = value;
                    this.SendPropertyChanged("ShipPostalCode");
                    this.OnShipPostalCodeChanged();
                }
            }
        }
        
        [Column(Storage="_ShipCountry", DbType="NVarChar(15)")]
        public string ShipCountry
        {
            get
            {
                return this._ShipCountry;
            }
            set
            {
                if ((this._ShipCountry != value))
                {
                    this.OnShipCountryChanging(value);
                    this.SendPropertyChanging();
                    this._ShipCountry = value;
                    this.SendPropertyChanged("ShipCountry");
                    this.OnShipCountryChanged();
                }
            }
        }
        
        [Association(Name="Order_Order_Detail", Storage="_Order_Details", OtherKey="OrderID")]
        public EntitySet<Order_Detail> Order_Details
        {
            get
            {
                return this._Order_Details;
            }
            set
            {
                this._Order_Details.Assign(value);
            }
        }
        
        public event PropertyChangingEventHandler PropertyChanging;
        
        public event PropertyChangedEventHandler PropertyChanged;
        
        protected virtual void SendPropertyChanging()
        {
            if ((this.PropertyChanging != null))
            {
                this.PropertyChanging(this, emptyChangingEventArgs);
            }
        }
        
        protected virtual void SendPropertyChanged(String propertyName)
        {
            if ((this.PropertyChanged != null))
            {
                this.PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
            }
        }
        
        private void attach_Order_Details(Order_Detail entity)
        {
            this.SendPropertyChanging();
            entity.Order = this;
            this.SendPropertyChanged("Order_Details");
        }
        
        private void detach_Order_Details(Order_Detail entity)
        {
            this.SendPropertyChanging();
            entity.Order = null;
            this.SendPropertyChanged("Order_Details");
        }
    }
    
    [Table(Name="dbo.[Order Details]")]
    public partial class Order_Detail : INotifyPropertyChanging, INotifyPropertyChanged
    {
        
        private static PropertyChangingEventArgs emptyChangingEventArgs = new PropertyChangingEventArgs(String.Empty);
        
        private int _OrderID;
        
        private int _ProductID;
        
        private decimal _UnitPrice;
        
        private short _Quantity;
        
        private float _Discount;
        
        private EntityRef<Order> _Order;
        
    Extensibility Method Definitions#region Extensibility Method Definitions
    partial void OnLoaded();
    partial void OnValidate();
    partial void OnCreated();
    partial void OnOrderIDChanging(int value);
    partial void OnOrderIDChanged();
    partial void OnProductIDChanging(int value);
    partial void OnProductIDChanged();
    partial void OnUnitPriceChanging(decimal value);
    partial void OnUnitPriceChanged();
    partial void OnQuantityChanging(short value);
    partial void OnQuantityChanged();
    partial void OnDiscountChanging(float value);
    partial void OnDiscountChanged();
    #endregion
        
        public Order_Detail()
        {
            OnCreated();
            this._Order = default(EntityRef<Order>);
        }
        
        [Column(Storage="_OrderID", DbType="Int NOT NULL", IsPrimaryKey=true)]
        public int OrderID
        {
            get
            {
                return this._OrderID;
            }
            set
            {
                if ((this._OrderID != value))
                {
                    if (this._Order.HasLoadedOrAssignedValue)
                    {
                        throw new System.Data.Linq.ForeignKeyReferenceAlreadyHasValueException();
                    }
                    this.OnOrderIDChanging(value);
                    this.SendPropertyChanging();
                    this._OrderID = value;
                    this.SendPropertyChanged("OrderID");
                    this.OnOrderIDChanged();
                }
            }
        }
        
        [Column(Storage="_ProductID", DbType="Int NOT NULL", IsPrimaryKey=true)]
        public int ProductID
        {
            get
            {
                return this._ProductID;
            }
            set
            {
                if ((this._ProductID != value))
                {
                    this.OnProductIDChanging(value);
                    this.SendPropertyChanging();
                    this._ProductID = value;
                    this.SendPropertyChanged("ProductID");
                    this.OnProductIDChanged();
                }
            }
        }
        
        [Column(Storage="_UnitPrice", DbType="Money NOT NULL")]
        public decimal UnitPrice
        {
            get
            {
                return this._UnitPrice;
            }
            set
            {
                if ((this._UnitPrice != value))
                {
                    this.OnUnitPriceChanging(value);
                    this.SendPropertyChanging();
                    this._UnitPrice = value;
                    this.SendPropertyChanged("UnitPrice");
                    this.OnUnitPriceChanged();
                }
            }
        }
        
        [Column(Storage="_Quantity", DbType="SmallInt NOT NULL")]
        public short Quantity
        {
            get
            {
                return this._Quantity;
            }
            set
            {
                if ((this._Quantity != value))
                {
                    this.OnQuantityChanging(value);
                    this.SendPropertyChanging();
                    this._Quantity = value;
                    this.SendPropertyChanged("Quantity");
                    this.OnQuantityChanged();
                }
            }
        }
        
        [Column(Storage="_Discount", DbType="Real NOT NULL")]
        public float Discount
        {
            get
            {
                return this._Discount;
            }
            set
            {
                if ((this._Discount != value))
                {
                    this.OnDiscountChanging(value);
                    this.SendPropertyChanging();
                    this._Discount = value;
                    this.SendPropertyChanged("Discount");
                    this.OnDiscountChanged();
                }
            }
        }
        
        [Association(Name="Order_Order_Detail", Storage="_Order", ThisKey="OrderID", IsForeignKey=true)]
        public Order Order
        {
            get
            {
                return this._Order.Entity;
            }
            set
            {
                Order previousValue = this._Order.Entity;
                if (((previousValue != value) 
                            || (this._Order.HasLoadedOrAssignedValue == false)))
                {
                    this.SendPropertyChanging();
                    if ((previousValue != null))
                    {
                        this._Order.Entity = null;
                        previousValue.Order_Details.Remove(this);
                    }
                    this._Order.Entity = value;
                    if ((value != null))
                    {
                        value.Order_Details.Add(this);
                        this._OrderID = value.OrderID;
                    }
                    else
                    {
                        this._OrderID = default(int);
                    }
                    this.SendPropertyChanged("Order");
                }
            }
        }
        
        public event PropertyChangingEventHandler PropertyChanging;
        
        public event PropertyChangedEventHandler PropertyChanged;
        
        protected virtual void SendPropertyChanging()
        {
            if ((this.PropertyChanging != null))
            {
                this.PropertyChanging(this, emptyChangingEventArgs);
            }
        }
        
        protected virtual void SendPropertyChanged(String propertyName)
        {
            if ((this.PropertyChanged != null))
            {
                this.PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
            }
        }
    }

本节介绍了O/R Designer的基本用法，下节讲一些比较高级的用法。O/R Designer相对与sqlmetal的好处就可以设计类的继承关系（下节再讲），而sqlmetal 相对于O/R Designer是可以一次性抽提所有表的信息，快速便捷。而且sqlmetal支持一些O/R Designer无法支持的信息提取。