//增加、删除、更新、查询公用       


string MyConn = "server=127.0.0.1;uid=数据库登录名;pwd=密码;database=数据库的名字;Trusted_Connection=no";
SqlConnection MyConnection = new SqlConnection(MyConn);


1、增加

string MyInsert = "想要执行的sql语句";
SqlCommand MyCommand = new SqlCommand(MyInsert, MyConnection);
MyConnection.Open();
MyCommand.ExecuteNonQuery();
MyConnection.Close();



2、删除


string MyDelete = "想要执行的sql语句";
SqlCommand MyCommand = new SqlCommand(MyDelete, MyConnection);
MyConnection.Open();
MyCommand.ExecuteNonQuery();
MyConnection.Close();

3、更新


string MyUpdate = "想要执行的sql语句";
SqlCommand MyCommand = new SqlCommand(MyUpdate, MyConnection);
MyConnection.Open();
MyCommand.ExecuteNonQuery();
MyConnection.Close();

4、查询


MyConn.Open();
SqlDataAdapter dap = new SqlDataAdapter("想要执行的sql语句",MyConn);
DataSet ds = new DataSet();//实例化DataSet类
dap.Fill(ds, "Table");//添加SQL语句并执行
dataGridView1.DataSource = ds.Tables[0].DefaultView;//显示数据