c#访问数据库的问题

Question

请问用c#访问sql数据库时候，adapter的update方法怎么用啊，我搞了好几遍都没搞懂，我是个初学者，还望各位大神不吝赐教啊

Answer 1

        private DataTable DT = new DataTable();
        private SqlDataAdapter SDA = new SqlDataAdapter();
        SqlConnection conn = new SqlConnection(DBClass.ConnStr);
        public datagreadForm()
        {
            InitializeComponent();
        }        private void datagreadForm_Load(object sender, EventArgs e)
        {
            button5.Enabled = false;
        }        private void selectbutton_Click(object sender, EventArgs e)
        {
            DT.Clear();
            string sqlstr = "select PlateNumber, goodsname,inputtime, grossweight, thetare, netweight, sunit, runit,  biaoji from daoyuntable where biaoji=0 and PlateNumber='" + textBox1.Text
                + "' and goodsname='" + textBox2.Text + "' and sunit='" + textBox3.Text + "' and runit='"+textBox4.Text+"' and bfname='"+DBClass.bangfangStr+"'";
            
            SqlCommand SCD = new SqlCommand(sqlstr, conn);
            SDA.SelectCommand = SCD;
            SDA.Fill(DT);
            dataGridView1.DataSource = DT;
            button5.Enabled = true;
        }        private void button5_Click(object sender, EventArgs e)
        {
            int k = 0;
            float a = 0;
            if (dataGridView1.RowCount > 0) 
            {
                for (int i = 0; i < dataGridView1.RowCount; i++)
                {                    if (bool.Parse(dataGridView1.Rows[i].Cells[8].Value.ToString()))
                    {
                        k = k + 1;
                        a=a+float.Parse(dataGridView1.Rows[i].Cells[3].Value.ToString());
                    }
                }
                textBox5.Text = dataGridView1.Rows[0].Cells[0].Value.ToString();
                textBox6.Text = dataGridView1.Rows[0].Cells[2].Value.ToString();
                textBox7.Text = a.ToString();//总的毛重数
                textBox8.Text = k.ToString();//记录修改的记录数               //label2.Text = "你选择了" + k.ToString() + "条记录  总的毛重是:"+a.ToString();
                //MessageBox.Show( "你选择了"+k.ToString()+"条记录");
            }
            try
            { 
                SqlCommandBuilder SCB = new SqlCommandBuilder(SDA);
                SDA.Update(DT);
            }
            catch (System.Exception ex) 
            {
                MessageBox.Show(ex.ToString()); 
                return; 
            }
            MessageBox.Show("更新成功!");
            button5.Enabled = false;        }        private void button1_Click(object sender, EventArgs e)
        {
            chehaoForm dlg = new chehaoForm(textBox1.Text);
            dlg.ShowDialog();
            textBox1.Text = dlg.chehaoValue;
        }        private void button2_Click(object sender, EventArgs e)
        {
            appClass.IDStr = 2;
            unitForm dlg = new unitForm(textBox2.Text);
            dlg.ShowDialog();            textBox2.Text = dlg.unitValue;
        }        private void button3_Click(object sender, EventArgs e)
        {
            appClass.IDStr = 1;
            unitForm dlg = new unitForm(textBox3.Text);
            dlg.ShowDialog();
            textBox3.Text = dlg.unitValue;
        }        private void button4_Click(object sender, EventArgs e)
        {
            appClass.IDStr = 1;
            unitForm dlg = new unitForm(textBox4.Text);
            dlg.ShowDialog();
            textBox4.Text = dlg.unitValue;
        }

Answer 2

简言之，为Adapter实现CUD操作所需的Command是先决条件。大致就是下面这个样子。不过可以用CommandBuilder省一些事。
string sql = @".......";
adapter = new adapter(sql, conn);
adapter.updatecommand = new command();
adapter.insertcommand = new command();
adapter.deletecommand = new command()..... .....adapter.Update();

Answer 3

偶还是觉得用Linq To SQL访问数据库比较简单...