微软数据开发技术

try
            {
                // Create a new adapter and give it a query to fetch sales order, contact, 
                // address, and product information for sales in the year 2002. Point connection 
                // information to the configuration setting "AdventureWorks".
                string connectionString = "Data Source=localhost;Initial Catalog=AdventureWorks;"
                    + "Integrated Security=true;";
                SqlDataAdapter da = new SqlDataAdapter(
                        "SELECT SalesOrderID, ContactID, OrderDate, OnlineOrderFlag, " +
                        "TotalDue, SalesOrderNumber, Status, ShipToAddressID, BillToAddressID " +
                        "FROM Sales.SalesOrderHeader " +
                        "WHERE DATEPART(YEAR, OrderDate) = @year; " +
                "SELECT d.SalesOrderID, d.SalesOrderDetailID, d.OrderQty, " +
                        "d.ProductID, d.UnitPrice " +
                        "FROM Sales.SalesOrderDetail d " +
                        "INNER JOIN Sales.SalesOrderHeader h " +
                        "ON d.SalesOrderID = h.SalesOrderID  " +
                        "WHERE DATEPART(YEAR, OrderDate) = @year; " +
                "SELECT p.ProductID, p.Name, p.ProductNumber, p.MakeFlag, " +
                        "p.Color, p.ListPrice, p.Size, p.Class, p.Style, p.Weight  " +
                        "FROM Production.Product p; " +
                "SELECT DISTINCT a.AddressID, a.AddressLine1, a.AddressLine2, " +
                        "a.City, a.StateProvinceID, a.PostalCode " +
                        "FROM Person.Address a " +
                        "INNER JOIN Sales.SalesOrderHeader h " +
                        "ON  a.AddressID = h.ShipToAddressID OR a.AddressID = h.BillToAddressID " +
                        "WHERE DATEPART(YEAR, OrderDate) = @year; " +
                "SELECT DISTINCT c.ContactID, c.Title, c.FirstName, " +
                        "c.LastName, c.EmailAddress, c.Phone " +
                        "FROM Person.Contact c " +
                        "INNER JOIN Sales.SalesOrderHeader h " +
                        "ON c.ContactID = h.ContactID " +
                        "WHERE DATEPART(YEAR, OrderDate) = @year;",
                    connectionString);
                // Add table mappings.
                da.SelectCommand.Parameters.AddWithValue("@year", 2002);
                da.TableMappings.Add("Table", "SalesOrderHeader");
                da.TableMappings.Add("Table1", "SalesOrderDetail");
                da.TableMappings.Add("Table2", "Product");
                da.TableMappings.Add("Table3", "Address");
                da.TableMappings.Add("Table4", "Contact");
                // Fill the DataSet.
                da.Fill(ds);
                // Add data relations.
                DataTable orderHeader = ds.Tables["SalesOrderHeader"];
                DataTable orderDetail = ds.Tables["SalesOrderDetail"];
                DataRelation order = new DataRelation("SalesOrderHeaderDetail",
                                         orderHeader.Columns["SalesOrderID"],
                                         orderDetail.Columns["SalesOrderID"], true);
                ds.Relations.Add(order);

                DataTable contact = ds.Tables["Contact"];
                DataTable orderHeader2 = ds.Tables["SalesOrderHeader"];
                DataRelation orderContact = new DataRelation("SalesOrderContact",
                                                contact.Columns["ContactID"],
                                                orderHeader2.Columns["ContactID"], true);
                ds.Relations.Add(orderContact);
            }
            catch (SqlException ex)
            {
                Console.WriteLine("SQL exception occurred: " + ex.Message);
            }

// Fill the DataSet.
DataSet ds = new DataSet();
ds.Locale = CultureInfo.InvariantCulture;
FillDataSet(ds);
DataTable orders = ds.Tables["SalesOrderHeader"];
DataTable details = ds.Tables["SalesOrderDetail"];
var query =
    from order in orders.AsEnumerable()
    join detail in details.AsEnumerable()
    on order.Field<int>("SalesOrderID") equals
        detail.Field<int>("SalesOrderID")
    where order.Field<bool>("OnlineOrderFlag") == true
    && order.Field<DateTime>("OrderDate").Month == 8
    select new
    {
        SalesOrderID =
            order.Field<int>("SalesOrderID"),
        SalesOrderDetailID =
            detail.Field<int>("SalesOrderDetailID"),
        OrderDate =
            order.Field<DateTime>("OrderDate"),
        ProductID =
            detail.Field<int>("ProductID")
    };
foreach (var order in query)
{
    Console.WriteLine("{0}\t{1}\t{2:d}\t{3}",
        order.SalesOrderID,
        order.SalesOrderDetailID,
        order.OrderDate,
        order.ProductID);
}

[global::System.Data.Linq.Mapping.DatabaseAttribute(Name = "Northwind")]
        public partial class LingToSqlDataContext : System.Data.Linq.DataContext
        {
            public System.Data.Linq.Table<Products> Products
            {
                get
                {
                    return this.GetTable<Products>();
                }
            }

            public System.Data.Linq.Table<Categories> Categories
            {
                get
                {
                    return this.GetTable<Categories>();
                }
            }
        }

        [global::System.Data.Linq.Mapping.TableAttribute(Name = "dbo.Categories")]
        public partial class Categories : INotifyPropertyChanging, INotifyPropertyChanged
        {

            private static PropertyChangingEventArgs emptyChangingEventArgs = new PropertyChangingEventArgs(String.Empty);

            private int _CategoryID;

            private string _CategoryName;

            private string _Description;

            private System.Data.Linq.Binary _Picture;

            private EntitySet<Products> _Products;

            [global::System.Data.Linq.Mapping.ColumnAttribute(Storage = "_CategoryID", AutoSync = AutoSync.OnInsert, DbType = "Int NOT NULL IDENTITY", IsPrimaryKey = true, IsDbGenerated = true)]
            public int CategoryID
            {
                get
                {
                    return this._CategoryID;
                }
                set
                {
                    if ((this._CategoryID != value))
                    {
                        this.OnCategoryIDChanging(value);
                        this.SendPropertyChanging();
                        this._CategoryID = value;
                        this.SendPropertyChanged("CategoryID");
                        this.OnCategoryIDChanged();
                    }
                }
            }
        }

public static void TestLinqToSqlSimple()
        {
            DataContext dc = new DataContext(ConfigurationManager.ConnectionStrings["Northwind"].ConnectionString);
            Table<Category> categoryTable = dc.GetTable<Category>();
            dc.Log = Console.Out;

            IQueryable<Category> query = from r in categoryTable where r.CategoryID > 1 select r;

            foreach (var item in query)
            {
                Console.WriteLine("{0}, {1}", item.CategoryID, item.CategoryName);
            }

            Category newCat = new Category();
            newCat.CategoryName = "test";
            categoryTable.InsertOnSubmit(newCat);

            dc.SubmitChanges();

            foreach (var item in query)
            {
                Console.WriteLine("{0}, {1}", item.CategoryID, item.CategoryName);
            }
        }

        [Table(Name = "Categories")]
        class Category
        {
            private int _CategoryID;

            private string _CategoryName;

            [Column(IsPrimaryKey = true, Storage = "_CategoryID", IsDbGenerated = true)]
            public int CategoryID
            {
                get
                {
                    return _CategoryID;
                }
                set
                {
                    _CategoryID = value;
                }
            }

            [Column(Storage = "_CategoryName")]
            public string CategoryName
            {
                get
                {
                    return _CategoryName;
                }
                set
                {
                    _CategoryName = value;
                }
            }
        }

// Northwnd inherits from System.Data.Linq.DataContext.
Northwnd nw = new Northwnd(@"northwnd.mdf");
Customer cust = new Customer();
cust.CompanyName = "SomeCompany";
cust.City = "London";
cust.CustomerID = "98128";
cust.PostalCode = "55555";
cust.Phone = "555-555-5555";
nw.Customers.InsertOnSubmit(cust);
// At this point, the new Customer object is added in the object model.
// In LINQ to SQL, the change is not sent to the database until
// SubmitChanges is called.
nw.SubmitChanges();

Northwnd nw = new Northwnd(@"northwnd.mdf");
var cityNameQuery =
    from cust in nw.Customers
    where cust.City.Contains("London")
    select cust;
foreach (var customer in cityNameQuery)
{
    if (customer.City == "London")
    {
        customer.City = "London - Metro";
    }
}
nw.SubmitChanges();

Northwnd nw = new Northwnd(@"northwnd.mdf");
var deleteIndivCust =
    from cust in nw.Customers
    where cust.CustomerID == "98128"
    select cust;
if (deleteIndivCust.Count() > 0)
{
    nw.Customers.DeleteOnSubmit(deleteIndivCust.First());
    nw.SubmitChanges();
}

public partial class DataSet1 : global::System.Data.DataSet {
        
        private ProductsDataTable tableProducts;
        
        private CategoriesDataTable tableCategories;
        
        private global::System.Data.DataRelation relationFK_Products_Categories;
}
 
        public partial class CategoriesDataTable : global::System.Data.TypedTableBase<CategoriesRow> {
            
            private global::System.Data.DataColumn columnCategoryID;
            
            private global::System.Data.DataColumn columnCategoryName;
            
            private global::System.Data.DataColumn columnDescription;
            
            private global::System.Data.DataColumn columnPicture;
}
 
        public partial class CategoriesRow : global::System.Data.DataRow {
            
            private CategoriesDataTable tableCategories;
            
            internal CategoriesRow(global::System.Data.DataRowBuilder rb) : 
                    base(rb) {
                this.tableCategories = ((CategoriesDataTable)(this.Table));
            }
            
            public int CategoryID {
                get {
                    return ((int)(this[this.tableCategories.CategoryIDColumn]));
                }
                set {
                    this[this.tableCategories.CategoryIDColumn] = value;
                }
            }
}

public static void TestSchema()
        {
            var settings = ConfigurationManager.ConnectionStrings["Northwind"];
            using (SqlConnection conn = new SqlConnection(settings.ConnectionString))
            {
                conn.Open();
                var res = conn.GetSchema();
                PrintTable(res);   res = conn.GetSchema("Tables");
                PrintTable(res);   SqlCommand command = new SqlCommand("select * from dbo.customers", conn);
                var read = command.ExecuteReader(CommandBehavior.SchemaOnly);   res = read.GetSchemaTable();
                PrintTable(res);
            }
        }

        private static void PrintTable(DataTable dt)
        {
            Console.WriteLine("*** {0} *****************************************", dt.TableName);
            foreach (DataColumn column in dt.Columns)
            {
                Console.Write(column.ColumnName + "\t");
            }
            Console.WriteLine();   foreach (DataRow dataRow in dt.Rows)
            {
                foreach (DataColumn dataColumn in dt.Columns)
                {
                    Console.Write(dataRow[dataColumn] + "\t");
                }
                Console.WriteLine();
            }
        }

// Assumes that connection is a valid SqlConnection object.
SqlCommand command = new SqlCommand(
  "SELECT pub_id, logo FROM pub_info", connection);
FileStream stream;                          
BinaryWriter writer;                        
int bufferSize = 100;                   
byte[] outByte = new byte[bufferSize];  
long retval;                            
long startIndex = 0;                    
string pubID = "";   
                  
connection.Open();
SqlDataReader reader = command.ExecuteReader(CommandBehavior.SequentialAccess);
while (reader.Read())
{
  pubID = reader.GetString(0);  
  stream = new FileStream(
    "logo" + pubID + ".bmp", FileMode.OpenOrCreate, FileAccess.Write);
  writer = new BinaryWriter(stream);

  startIndex = 0;
  retval = reader.GetBytes(1, startIndex, outByte, 0, bufferSize);

  while (retval == bufferSize)
  {
    writer.Write(outByte);
    writer.Flush();
    startIndex += bufferSize;
    retval = reader.GetBytes(1, startIndex, outByte, 0, bufferSize);
  }

  writer.Write(outByte, 0, (int)retval - 1);
  writer.Flush();

  writer.Close();
  stream.Close();
}

reader.Close();
connection.Close();