此处将资料从数据库得出后显在DataGridView上显示。然后变更数据。变更数据的方法在按钮事件中。 资料显示方法不用多说。 更新时主要用到SqlCommandBuilder类和SqlDataAdapter.Update()方法。 SqlCommandBuilder对象负责生成用于更新数据库的SQL语句,不必自己创建这些语句。 UpDate方法自动遍历DataTable中的行,以找出需要对数据库作出变动。Rows集合中每个DataRow对象都具有属性RowState,可以跟踪此行是否已删除、添加、修改,还是未作变动。所作的任何变化都会反映到数据库中。 例:更新表中内容: using System.Data.SqlClient; namespace UpdatingData
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
btnUpdate.Click += new EventHandler(btnUpdate_Click);
UpdateData();
}
string sConnection = "Data Source=scott;Initial Catalog=northwind;Persist Security Info=True;User ID=sa;PassWord=sa123";
DataSet dsSet = new DataSet();
SqlDataAdapter sdaAdapter = null;
SqlCommandBuilder scbBuilder = null;
PRivate void UpdateData()
{
//建立Connection
SqlConnection scConnection = new SqlConnection(sConnection);
//建立Command
SqlCommand scCommand = scConnection.CreateCommand();
scCommand.CommandText = "select customerID,contactName from customers";
//建立Adapter
sdaAdapter = new SqlDataAdapter(scCommand);
//该对象负责生成用于更新数据库的SQL语句,不必自己创建这些语句
scbBuilder = new SqlCommandBuilder(sdaAdapter); //得到数据
sdaAdapter.Fill(dsSet, "customers");
dgvView.DataSource = dsSet.Tables["customers"]; } void btnUpdate_Click(object sender, EventArgs e)
{
//设置值
dsSet.Tables["customers"].Rows[3]["contactName"] = "Thomas Hardy";
//更新数据(UpDate方法自动遍历DataTable中的行,以找出需要对数据库作出变动)
//Rows集合中每个DataRow对象都具有属性RowState,可以跟踪此行是否已删除、添加、修改,还是未作变动。所作的任何变化都会反映到数据库中。
sdaAdapter.Update(dsSet, "customers");
dgvView.DataSource = dsSet.Tables["customers"]; }
}
}
例:在表中增加行 using System.Data.SqlClient; namespace AddingData
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
btnAdd.Click += new EventHandler(btnAdd_Click); UpdateData();
}
string sConnection = "Data Source=scott;Initial Catalog=northwind;Persist Security Info=True;User ID=sa;Password=sa123";
DataSet dsSet = new DataSet();
SqlDataAdapter sdaAdapter = null;
SqlCommandBuilder scbBuilder = null;
private void UpdateData()
{
//建立Connection
SqlConnection scConnection = new SqlConnection(sConnection);
//建立Command
SqlCommand scCommand = scConnection.CreateCommand();
scCommand.CommandText = "select customerID,companyName from customers";
//建立Adapter
sdaAdapter = new SqlDataAdapter(scCommand);
//该对象负责生成用于更新数据库的SQL语句,不必自己创建这些语句
scbBuilder = new SqlCommandBuilder(sdaAdapter); //得到数据
sdaAdapter.Fill(dsSet, "customers");
dgvView.DataSource = dsSet.Tables["customers"];
} void btnAdd_Click(object sender, EventArgs e)
{
AddRow();
}
private void AddRow()
{
//新建表中的行
DataRow drRow = dsSet.Tables["customers"].NewRow();
drRow["customerID"] = "ZaCzi";
drRow["companyName"] = "Zachary Zithers Ltd.";
//增加行
dsSet.Tables["customers"].Rows.Add(drRow); //更新表
sdaAdapter.Update(dsSet, "customers");
//显示
dgvView.DataSource = dsSet.Tables["customers"];
}
}
}
|