09存储过程查询多个结果集

1 创建Northwind代码文件

執行：sqlmetal /code:"c:\linqtest7\northwind.cs" /language:csharp "c:\linqtest7\northwnd.mdf" /sprocs /functions /pluralize

1.2 Northwind 的储存过程

[Get Customer And Orders]

1.3 存储过程映射的代码

下面为工具生成代码。

  /// <summary>
    /// 獲取客戶信息和訂單信息
    /// </summary>
    /// <param name="customerID">客戶ID(輸入)</param>
    /// <returns>
    /// 返回2個結果：客戶信息和訂單信息
    /// SELECT * FROM Customers AS c WHERE c.CustomerID = @CustomerID
    /// SELECT * FROM Orders AS o WHERE o.CustomerID = @CustomerID
    /// </returns>
    /// <remarks>
    /// Function:對應到數據庫的Procedure名字
    /// ResultType:返回結果的類型，必須指定每一個結果的類型
    /// IMultipleResults：表示返回多個結果
    /// </remarks>
    [Function(Name = "dbo.Get Customer And Orders")]
    [ResultType(typeof(GetCustomerAndOrdersResult1))]
    [ResultType(typeof(GetCustomerAndOrdersResult2))]
    public IMultipleResults GetCustomerAndOrders([Parameter(Name = "CustomerID", DbType = "NChar(5)")] string customerID)
    {
        IExecuteResult result = this.ExecuteMethodCall(this, ((MethodInfo)(MethodInfo.GetCurrentMethod())), customerID);
        return ((IMultipleResults)(result.ReturnValue));
    }

注意：返回多個結果使用IMultipleResults

1.4 GetCustomerAndOrdersResult1类

public partial class GetCustomerAndOrdersResult1
{

    private string _CustomerID;

    private string _CompanyName;

    private string _ContactName;

    private string _ContactTitle;

    private string _Address;

    private string _City;

    private string _Region;

    private string _PostalCode;

    private string _Country;

    private string _Phone;

    private string _Fax;

    public GetCustomerAndOrdersResult1()
    {
    }

    [Column(Storage = "_CustomerID", DbType = "NChar(5)")]
    public string CustomerID
    {
        get
        {
            return this._CustomerID;
        }
        set
        {
            if ((this._CustomerID != value))
            {
                this._CustomerID = value;
            }
        }
    }

    [Column(Storage = "_CompanyName", DbType = "NVarChar(40)")]
    public string CompanyName
    {
        get
        {
            return this._CompanyName;
        }
        set
        {
            if ((this._CompanyName != value))
            {
                this._CompanyName = value;
            }
        }
    }

    [Column(Storage = "_ContactName", DbType = "NVarChar(30)")]
    public string ContactName
    {
        get
        {
            return this._ContactName;
        }
        set
        {
            if ((this._ContactName != value))
            {
                this._ContactName = value;
            }
        }
    }

    [Column(Storage = "_ContactTitle", DbType = "NVarChar(30)")]
    public string ContactTitle
    {
        get
        {
            return this._ContactTitle;
        }
        set
        {
            if ((this._ContactTitle != value))
            {
                this._ContactTitle = value;
            }
        }
    }

    [Column(Storage = "_Address", DbType = "NVarChar(60)")]
    public string Address
    {
        get
        {
            return this._Address;
        }
        set
        {
            if ((this._Address != value))
            {
                this._Address = value;
            }
        }
    }

    [Column(Storage = "_City", DbType = "NVarChar(15)")]
    public string City
    {
        get
        {
            return this._City;
        }
        set
        {
            if ((this._City != value))
            {
                this._City = value;
            }
        }
    }

    [Column(Storage = "_Region", DbType = "NVarChar(15)")]
    public string Region
    {
        get
        {
            return this._Region;
        }
        set
        {
            if ((this._Region != value))
            {
                this._Region = value;
            }
        }
    }

    [Column(Storage = "_PostalCode", DbType = "NVarChar(10)")]
    public string PostalCode
    {
        get
        {
            return this._PostalCode;
        }
        set
        {
            if ((this._PostalCode != value))
            {
                this._PostalCode = value;
            }
        }
    }

    [Column(Storage = "_Country", DbType = "NVarChar(15)")]
    public string Country
    {
        get
        {
            return this._Country;
        }
        set
        {
            if ((this._Country != value))
            {
                this._Country = value;
            }
        }
    }

    [Column(Storage = "_Phone", DbType = "NVarChar(24)")]
    public string Phone
    {
        get
        {
            return this._Phone;
        }
        set
        {
            if ((this._Phone != value))
            {
                this._Phone = value;
            }
        }
    }

    [Column(Storage = "_Fax", DbType = "NVarChar(24)")]
    public string Fax
    {
        get
        {
            return this._Fax;
        }
        set
        {
            if ((this._Fax != value))
            {
                this._Fax = value;
            }
        }
    }
}

1.6 GetCustomerAndOrdersResult2类

public partial class GetCustomerAndOrdersResult2
{

    private System.Nullable<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;

    public GetCustomerAndOrdersResult2()
    {
    }

    [Column(Storage = "_OrderID", DbType = "Int")]
    public System.Nullable<int> OrderID
    {
        get
        {
            return this._OrderID;
        }
        set
        {
            if ((this._OrderID != value))
            {
                this._OrderID = value;
            }
        }
    }

    [Column(Storage = "_CustomerID", DbType = "NChar(5)")]
    public string CustomerID
    {
        get
        {
            return this._CustomerID;
        }
        set
        {
            if ((this._CustomerID != value))
            {
                this._CustomerID = value;
            }
        }
    }

    [Column(Storage = "_EmployeeID", DbType = "Int")]
    public System.Nullable<int> EmployeeID
    {
        get
        {
            return this._EmployeeID;
        }
        set
        {
            if ((this._EmployeeID != value))
            {
                this._EmployeeID = value;
            }
        }
    }

    [Column(Storage = "_OrderDate", DbType = "DateTime")]
    public System.Nullable<System.DateTime> OrderDate
    {
        get
        {
            return this._OrderDate;
        }
        set
        {
            if ((this._OrderDate != value))
            {
                this._OrderDate = value;
            }
        }
    }

    [Column(Storage = "_RequiredDate", DbType = "DateTime")]
    public System.Nullable<System.DateTime> RequiredDate
    {
        get
        {
            return this._RequiredDate;
        }
        set
        {
            if ((this._RequiredDate != value))
            {
                this._RequiredDate = value;
            }
        }
    }

    [Column(Storage = "_ShippedDate", DbType = "DateTime")]
    public System.Nullable<System.DateTime> ShippedDate
    {
        get
        {
            return this._ShippedDate;
        }
        set
        {
            if ((this._ShippedDate != value))
            {
                this._ShippedDate = value;
            }
        }
    }

    [Column(Storage = "_ShipVia", DbType = "Int")]
    public System.Nullable<int> ShipVia
    {
        get
        {
            return this._ShipVia;
        }
        set
        {
            if ((this._ShipVia != value))
            {
                this._ShipVia = value;
            }
        }
    }

    [Column(Storage = "_Freight", DbType = "Money")]
    public System.Nullable<decimal> Freight
    {
        get
        {
            return this._Freight;
        }
        set
        {
            if ((this._Freight != value))
            {
                this._Freight = value;
            }
        }
    }

    [Column(Storage = "_ShipName", DbType = "NVarChar(40)")]
    public string ShipName
    {
        get
        {
            return this._ShipName;
        }
        set
        {
            if ((this._ShipName != value))
            {
                this._ShipName = value;
            }
        }
    }

    [Column(Storage = "_ShipAddress", DbType = "NVarChar(60)")]
    public string ShipAddress
    {
        get
        {
            return this._ShipAddress;
        }
        set
        {
            if ((this._ShipAddress != value))
            {
                this._ShipAddress = value;
            }
        }
    }

    [Column(Storage = "_ShipCity", DbType = "NVarChar(15)")]
    public string ShipCity
    {
        get
        {
            return this._ShipCity;
        }
        set
        {
            if ((this._ShipCity != value))
            {
                this._ShipCity = value;
            }
        }
    }

    [Column(Storage = "_ShipRegion", DbType = "NVarChar(15)")]
    public string ShipRegion
    {
        get
        {
            return this._ShipRegion;
        }
        set
        {
            if ((this._ShipRegion != value))
            {
                this._ShipRegion = value;
            }
        }
    }

    [Column(Storage = "_ShipPostalCode", DbType = "NVarChar(10)")]
    public string ShipPostalCode
    {
        get
        {
            return this._ShipPostalCode;
        }
        set
        {
            if ((this._ShipPostalCode != value))
            {
                this._ShipPostalCode = value;
            }
        }
    }

    [Column(Storage = "_ShipCountry", DbType = "NVarChar(15)")]
    public string ShipCountry
    {
        get
        {
            return this._ShipCountry;
        }
        set
        {
            if ((this._ShipCountry != value))
            {
                this._ShipCountry = value;
            }
        }
    }
}

2 新建項目

新建Window Form App ,命名為SprocOnlyApp

3 添加引用和Namespace

加入 System.Data.Linq.dll

using System.Data.Linq;

4 将Northwind代码添加到项目

northwind.cs添加到SprocOnlyApp

5 设计界面

在Form上拖一个按钮，用来调用程式。

6 测试

 private void button5_Click(object sender, EventArgs e)
        {
            Northwnd db = new Northwnd(@"c:\data\northwnd.mdf");

            // 聲明變量用來儲存查詢定義
            IMultipleResults result = db.GetCustomerAndOrders("ALFKI");
            
            // ------ 方法一 使用專為結果定義的類------
            // 執行查詢並且輸出結果
            // 客戶
            foreach (GetCustomerAndOrdersResult1 cust in
                result.GetResult<GetCustomerAndOrdersResult1>())
            {
                Console.WriteLine(cust.CustomerID);
            }
            // Pause to view company names; press Enter to continue.
            Console.WriteLine(" ------ Orders ------ ");
            // 訂單
            foreach (GetCustomerAndOrdersResult2 ord in
                result.GetResult<GetCustomerAndOrdersResult2>())
            {
                Console.WriteLine(ord.OrderID);
            }

            // ------ 方法二 使用根據數據庫表生成的類------
            Console.WriteLine(" == 使用根據數據庫表生成的類 == ");
            // 遇到結果是取表的部分有用的欄位，除非是繼承關係，否則不能使用。
            // 不好使用。
            foreach (Customer cust in result.GetResult<Customer>())
            {
                Console.WriteLine(cust.CustomerID);
            }
            foreach (Order ord in result.GetResult<Order>())
            {
                Console.WriteLine(ord.OrderID);
            }
        }

注意：IMultipleResults的功能-以变量返回顺序表示已对应函数或查询的结果。

ISingleResult的功能-表示拥有单一返回顺序之已对应函数的结果。