使用 DataSet 更新 TableAdapter - 更新需要有效的 DeleteCommand 错误

Posted 2023-05-07

【中文标题】使用 DataSet 更新 TableAdapter - 更新需要有效的 DeleteCommand 错误

【英文标题】：Update TableAdapter with DataSet - Update requires a valid DeleteCommand error

【发布时间】：2013-07-04 21:19:02

【问题描述】：

在下面的代码中，“当传递带有已删除行的 DataRow 集合时，更新需要有效的 DeleteCommand”。什么意思？

foreach (DataGridViewRow item in this.dataGridView2.SelectedRows)

    fuelStopsDataSet1.Tables[0].Rows[item.Index].Delete();


this.fuelStopsTableAdapter.Update(this.fuelStopsDataSet1.FuelStops);

【参考方案1】：

您可以在某些情况下自动创建 DeleteCommand（从 SelectCommand 推断）。

SqlDataAdapter da = new SqlDataAdapter("...SELECT Statement...", connection);
SqlCommandBuilder cmd_b = new SqlCommandBuilder(da); // this already creates 
// the Update- and DeleteCommands for the DA

这是一篇关于它的文章：http://msdn.microsoft.com/library/vstudio/tf579hcz.aspx

【参考方案2】：

这意味着您正在使用DataAdapter 更新包含已删除DataRows 的表（他们的RowState 是Deleted）。然后DataAdapter 使用指定的DeleteCommand 删除数据库中的这一行。但你没有提供。

所以你需要提供它。

MSDN 示例：

public static SqlDataAdapter CreateCustomerAdapter(
    SqlConnection connection)

    SqlDataAdapter adapter = new SqlDataAdapter();

    // Create the SelectCommand.
    SqlCommand command = new SqlCommand("SELECT * FROM Customers " +
        "WHERE Country = @Country AND City = @City", connection);

    // Add the parameters for the SelectCommand.
    command.Parameters.Add("@Country", SqlDbType.NVarChar, 15);
    command.Parameters.Add("@City", SqlDbType.NVarChar, 15);

    adapter.SelectCommand = command;

    // Create the InsertCommand.
    command = new SqlCommand(
        "INSERT INTO Customers (CustomerID, CompanyName) " +
        "VALUES (@CustomerID, @CompanyName)", connection);

    // Add the parameters for the InsertCommand.
    command.Parameters.Add("@CustomerID", SqlDbType.NChar, 5, "CustomerID");
    command.Parameters.Add("@CompanyName", SqlDbType.NVarChar, 40, "CompanyName");

    adapter.InsertCommand = command;

    // Create the UpdateCommand.
    command = new SqlCommand(
        "UPDATE Customers SET CustomerID = @CustomerID, CompanyName = @CompanyName " +
        "WHERE CustomerID = @oldCustomerID", connection);

    // Add the parameters for the UpdateCommand.
    command.Parameters.Add("@CustomerID", SqlDbType.NChar, 5, "CustomerID");
    command.Parameters.Add("@CompanyName", SqlDbType.NVarChar, 40, "CompanyName");
    SqlParameter parameter = command.Parameters.Add(
        "@oldCustomerID", SqlDbType.NChar, 5, "CustomerID");
    parameter.SourceVersion = DataRowVersion.Original;

    adapter.UpdateCommand = command;

    // Create the DeleteCommand.
    command = new SqlCommand(
        "DELETE FROM Customers WHERE CustomerID = @CustomerID", connection);

    // Add the parameters for the DeleteCommand.
    parameter = command.Parameters.Add(
        "@CustomerID", SqlDbType.NChar, 5, "CustomerID");
    parameter.SourceVersion = DataRowVersion.Original;

    adapter.DeleteCommand = command;

    return adapter;

最后一个命令是DeleteCommand。