asp.net无法更新数据库

有什么建议吗？

稍微清理一下您想要尝试的代码您应该处理IDisposable对象：

string ConnectionString = WebConfigurationManager.ConnectionStrings["dbnameConnectionString"].ConnectionString;
SqlConnection myConnection = new SqlConnection(ConnectionString);

myConnection.Open();
try
{
    string qry = "UPDATE customers SET firstname=@firstname WHERE cid=1";
    SqlCommand insertQuery = new SqlCommand(qry, myConnection);
    insertQuery.Parameters.Add(new SqlParameter("@firstname", txtFirstname.Text));
    insertQuery.ExecuteNonQuery();

    myConnection.Close();
}
catch (Exception ee)
{

}

---

您是否遇到异常？因此，您的数据库中没有cid=1？如果他遇到异常，则它已被捕获而未被执行@我只是为了测试而放弃try/catch。另外，如果您在关闭之前遇到异常，您将与发布的代码保持一个打开的连接。为了让我们能够帮助您，您必须更具体一点。执行此语句后rowsUpdated的值是多少？

string ConnectionString = // ...
using (var connection = new SqlConnection(ConnectionString))
using (var command = connection.CreateCommand())
{
    connection.Open();
    command.CommandText = "UPDATE customers SET firstname = @firstname WHERE cid=1";
    command.Parameters.AddWithValue("@firstname", txtFirstname.Text);
    var rowsUpdated = command.ExecuteNonQuery();
}