错误：当传递带有修改行的 DataRow 集合时，更新需要有效的 UpdateCommand

Question

我正在使用 Paging 来显示 datagridview 中的数据，但是当我尝试使用 updatebutton 更新任何数据时，应在 datagridview 以及数据库中更新数据。

但我收到此错误：

在传递 DataRow 集合时，更新需要有效的 UpdateCommand 修改后的行

发生在这一行：

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

下面是代码

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Select 命令创建了OleDbDataAdapter：

adp1 = new OleDbDataAdapter(cmd1);

OleDbDataAdapter 需要使用有效的Update、Insert, Delete 命令来保存数据，如下所示：

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

您只需要使用OleDbCommandBuilder 即可为您生成命令：

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

编辑

由于您在运行时更改OleDbDataAdapter的Select命令进行分页，因此您需要在每次保存数据时进行初始化：

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中的列上设置了主键。

Answer 3

我不得不将我的（递增）索引列更改为primary key of my table（正如 Eaint 建议的那样）。在此之后，我必须在设计器视图中拉出 DataSet.xsd，右键单击可视 DataTable 对象并选择配置。当 TableAdapter 配置向导打开时，我单击了高级选项按钮。我检查了生成插入、更新和删除语句复选框，然后确定并完成。在此之后（仍在设计器视图中），我选择了可​​视化 TableAdapter 对象，它为我提供了所有完整属性。 SQL 是自动生成的。我花了一段时间才找到它，所以我希望它对某人有所帮助。

Answer 4

感谢“@Chris”，上面的代码对我有用。 我需要指定更新时将更新的数据库表名称。 您可以在此处阅读更多相关信息：

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());
}