Question

我想使用DataGridView删除数据库中的多行或所有行。例如。如果DataGridView中有10行，则应选择并删除所有10行。以下是使用DataGridView删除数据库中单行的代码。

private void btnDeleteProduct_Click(object sender, EventArgs e)
    {
        ConnectionStringSettings conSettings = ConfigurationManager.ConnectionStrings["MyDBConnectionString"];
        string connectionString = conSettings.ConnectionString;

            if (ProductServicesDataGrid.CurrentRow.Selected)
            {
                string selectedCode = ProductServicesDataGrid.CurrentRow.Cells[0].Value.ToString();

                conn = new SqlConnection(connectionString);

                try
                {
                    conn.Open();
                    cmd = new SqlCommand("DELETE FROM ProductServices where ProductCode='" + selectedCode + "' ", conn);
                    sdr = cmd.ExecuteReader();
                    loadProductServicesTable();

                }
                catch (Exception ex)
                {

                    MessageBox.Show(ex.Message);
                }
                finally
                {
                    conn.Close();
                }
            }
            else
            {
                MessageBox.Show("Row is not Selected");
            }
    }

有人可以帮助我并修改我的代码吗？

Answer 1

首先，您不应该使用CurrentRow属性，因为它只返回一行。代替。使用SelectedRows集合并迭代它。

其次，从不在命令文本中连接参数。相反，请使用参数化查询。

//connection.Open is moved out of the loop, to avoid unnecessary open/close
conn = new SqlConnection(connectionString);
conn.Open();

try
{
    foreach (var row in ProductServicesDataGrid.SelectedRows)
    {
        string selectedCode = row.Cells[0].Value.ToString();

        try
        {
            cmd = new SqlCommand("DELETE FROM ProductServices where ProductCode=@productCode", conn);
            cmd.Parameters.Add(.Parameters.Add("productCode", SqlDbType.VarChar).Value = selectedCode;
            sdr = cmd.ExecuteReader();
            //this probably shouldn't be here, but outside the foreach loop.
            //that way table will be loaded after deletion of those n rows.
            //loadProductServicesTable();


    }
}
catch (Exception ex)
{
    MessageBox.Show(ex.Message);
}
finally
{
    conn.Close();
}

//refresh products after deletion
loadProductServicesTable();

如何删除DataGridView中的多个或所有行？

1 个答案: