對數據庫對象的操作可以編碼實現,當然.NET提供了更加方便的可視化機制可以幫助我們省卻很多麻煩。
首先,在項目中增加新項,選擇Dataset數據集,如圖所示:
比如新建一個CustomersXSD.xsd的數據集,下面將NorthWind數據庫中的Customers表拖到當前設計面板,如下如所示:
如圖所示,自動生成名為CustomersTableAdapter的Adapter對象,手動設置增加圖上三個方法,
其中GetByPrimaryKey方法如圖所示配置:
下面代碼演示如何使用CustomerXSD, CustomersTableAdapter來實現對數據表Customers增加一條記錄:
首先假設代碼中已經生成了表Customer對象類CustomersModel,代碼如下:注意加紅的部分
using Model;//數據庫實體類Model
using CustomersXSDTableAdapters;//引入Adapter命名空間
public class CustomersDAL
{
private CustomersTableAdapter _CustomersTableAdapter = null;
protected CustomersTableAdapter Adapter
{
get
{
if (_CustomersTableAdapter == null)
_CustomersTableAdapter = new CustomersTableAdapter();
return _CustomersTableAdapter;
}
}
//Get方法,得到表中所有的數據
public DataTable Get()
{
return Adapter.GetData();
}
// 根據主鍵得到數據表
public DataTable GetByPrimaryKey(String CustomerID)
{
return Adapter.GetByPrimaryKey(CustomerID);
}
//增加一條記錄
public bool Add(CustomersModel model)
{
CustomersXSD.CustomersDataTable TargetTable = new CustomersXSD.CustomersDataTable();
CustomersXSD.CustomersRow TargetRow = TargetTable.NewCustomersRow();
TargetRow.CustomerID = model.CustomerID;
TargetRow.CompanyName = model.CompanyName;
TargetRow.ContactName = model.ContactName;
TargetRow.ContactTitle = model.ContactTitle;
TargetRow.Address = model.Address;
TargetRow.City = model.City;
TargetRow.Region = model.Region;
TargetRow.PostalCode = model.PostalCode;
TargetRow.Country = model.Country;
TargetRow.Phone = model.Phone;
TargetRow.Fax = model.Fax;
TargetTable.AddCustomersRow(TargetRow);
int rowaffected = Adapter.Update(TargetTable);
return rowaffected == 1;
}
//更新一條記錄
public bool Update(CustomersModel model)
{
CustomersXSD.CustomersDataTable TargetTable = Adapter.GetByPrimaryKey(model.CustomerID);
if (TargetTable.Count == 0)
return false;
CustomersXSD.CustomersRow TargetRow = TargetTable[0];
TargetRow.CustomerID = model.CustomerID;
TargetRow.CompanyName = model.CompanyName;
TargetRow.ContactName = model.ContactName;
TargetRow.ContactTitle = model.ContactTitle;
TargetRow.Address = model.Address;
TargetRow.City = model.City;
TargetRow.Region = model.Region;
TargetRow.PostalCode = model.PostalCode;
TargetRow.Country = model.Country;
TargetRow.Phone = model.Phone;
TargetRow.Fax = model.Fax;
int rowsaffected = Adapter.Update(TargetRow);
return rowsaffected == 1;
}
//刪除一條記錄
public bool Delete(String CustomerID)
{
int rowsaffected = Adapter.DeleteByCustomerID(CustomerID);
return rowsaffected == 1;
}
}