Question

我正在使用Paging在datagridview中显示数据，但是当我尝试使用updatebutton数据更新任何数据时，应在datagridview以及数据库中更新。

但是我收到了这个错误：

更新在传递DataRow集合时需要有效的UpdateCommand 修改行

发生在这一行：

adp1.Update(dt);//here I am getting error

以下是代码

public partial class EditMediClgList : Form
    {        
        public EditMediClgList()
        {
            InitializeComponent();
            try
            {
                con = new OleDbConnection(@"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=db1.mdb");
                con.Open();
            }
            catch (Exception err)
            {
                MessageBox.Show("Error:" +err);
            }

            cmd1 = new OleDbCommand("Select * from MedicalColeges order by MedicalClgID", con);
            ds = new DataSet();
            adp1 = new OleDbDataAdapter(cmd1);
            adp1.Fill(ds, "MedicalColeges");
            dataGridView1.DataSource = ds;

            // Get total count of the pages; 
            this.CalculateTotalPages();
            // Load the first page of data; 
            this.dataGridView1.DataSource = GetCurrentRecords(1, con);

        }
        private void CalculateTotalPages()
        {
            int rowCount = ds.Tables["MedicalColeges"].Rows.Count;
            this.TotalPage = rowCount / PageSize;
            if (rowCount % PageSize > 0) // if remainder is more than  zero 
            {
                this.TotalPage += 1;
            }
        }
        private DataTable GetCurrentRecords(int page, OleDbConnection con)
        {
             dt = new DataTable();

            if (page == 1)
            {
                cmd2 = new OleDbCommand("Select TOP " + PageSize + " * from MedicalColeges ORDER BY MedicalClgID", con);
                // CurrentPageIndex++;
            }
            else
            {
                int PreviouspageLimit = (page - 1) * PageSize;

                cmd2 = new OleDbCommand("Select TOP " + PageSize +
                    " * from MedicalColeges " +
                    "WHERE MedicalClgID NOT IN " +
                "(Select TOP " + PreviouspageLimit + " MedicalClgID from MedicalColeges ORDER BY MedicalClgID) ", con); // +
                //"order by customerid", con);
            }
            try
            {
                // con.Open();
                this.adp1.SelectCommand = cmd2;
                this.adp1.Fill(dt);
                txtPaging.Text = string.Format("page{0} of {1} pages", this.CurrentPageIndex, this.TotalPage);
            }
            finally
            {
               // con.Close();
            }
            return dt;
        }

        private void button1_Click(object sender, EventArgs e)
        {
            try
            {                
                adp1.Update(dt);//here I am getting error
            }
            catch (Exception err)
            {
                MessageBox.Show(err.Message.ToString());
            }

        }
}

Answer 1

您仅使用OleDbDataAdapter命令创建了Select：

adp1 = new OleDbDataAdapter(cmd1);

OleDbDataAdapter 需要使用有效的Update，Insert, Delete命令来保存这样的数据：

adp1.Update(dt);//here I am getting error

您只需使用可为您生成命令的OleDbCommandBuilder：

adp1 = new OleDbDataAdapter();
adp1.SelectCommand = cmd1; // cmd1 is your SELECT command
OleDbCommandBuilder cb = new OleDbCommandBuilder(adp1);

修改

由于您在运行时更改了OleDbDataAdapter的Select命令以进行分页，因此每次保存数据时都需要初始化：

private void button1_Click(object sender, EventArgs e) { try { adp1.SelectCommand = cmd1; // cmd1 is your SELECT command OleDbCommandBuilder cb = new OleDbCommandBuilder(adp1); adp1.Update(dt); //here I hope you won't get error :-) } catch (Exception err) { MessageBox.Show(err.Message.ToString()); } }

Answer 2

可能是您在表中缺少主键。您需要确保在数据库表的列上设置主键。

Answer 3

我必须将我的（递增）索引列更改为primary key of my table（如Eaint建议的那样）。在此之后，我不得不在设计器视图中提取DataSet.xsd，右键单击visual DataTable对象并选择configure。 TableAdapter配置向导打开后，我单击了“高级选项”按钮。我选中了Generate Insert，Update和Delete语句复选框，然后单击OK和Finish。在此之后（仍然在设计师视图中），我选择了可视化的TableAdapter对象，它给了我所有的完整属性。 SQL是自动生成的。花了一段时间让我跟踪它，所以我希望它可以帮助别人。

Answer 4

感谢“ @Chris”，上面的代码对我有用。我需要指定在更新时将更新的数据库表名称。您可以在这里阅读有关此内容的更多信息：DataAdapter: Update unable to find TableMapping['Table'] or DataTable 'Table'

    // This Adapter and Dataset are used for Populating my datagridview, so I use them also when I need to Update the Datagridview

    SqlDataAdapter kundeTlfAdapter;
    DataSet kundeTlfDataSet; 

        try
        {
            SqlConnection connection = new SqlConnection("Data source=BG-1-PC\\SQLEXPRESS; Database = Advokathuset; User Id = abc; Password = abc;");
            SqlCommand cmd1 = new SqlCommand("Select* From Kunde_Tlf", connection);
            SqlCommandBuilder builder = new SqlCommandBuilder(kundeTlfAdapter);
            kundeTlfAdapter.SelectCommand = cmd1; // cmd1 is your SELECT command

            kundeTlfAdapter.Update(kundeTlfDataSet, "Kunde_Tlf"); //I get eror here if I dont add the name of the table that needs Update "Kunde_Tlf"
        }
        catch (Exception err)
        {
            MessageBox.Show(err.Message.ToString());
        }

错误：在传递带有已修改行的DataRow集合时，Update需要有效的UpdateCommand

4 个答案: