我在ADO.NET中手動編寫事務。我正在使用的示例重用了SqlCommand
,這似乎是一個好主意。重新使用SqlCommand進行轉換時,是否應該調用Parameters.Clear?
不過,我已經加入參數,以我的命令。
我的問題是:在下面的代碼,是command.Parameters.Clear()
正確的?還是我做錯了?
using (var connection = new SqlConnection(EomAppCommon.EomAppSettings.ConnStr))
{
connection.Open();
SqlTransaction transaction = connection.BeginTransaction();
SqlCommand command = connection.CreateCommand();
command.Transaction = transaction;
try
{
foreach (var itemIDs in this.SelectedItemIds)
{
command.CommandText = "UPDATE Item SET payment_method_id = @batchID WHERE id in (@itemIDs)";
// IS THE FOLLOWING CORRECT?
command.Parameters.Clear();
command.Parameters.Add(new SqlParameter("@batchID", batchID));
command.Parameters.Add(new SqlParameter("@itemIDs", itemIDs));
command.ExecuteNonQuery();
}
transaction.Commit();
}
catch (Exception ex)
{
MessageBox.Show("Failed to update payment batches, rolling back." + ex.Message);
try
{
transaction.Rollback();
}
catch (Exception exRollback)
{
if (!(exRollback is InvalidOperationException)) // connection closed or transaction already rolled back on the server.
{
MessageBox.Show("Failed to roll back. " + exRollback.Message);
}
}
}
}
爲什麼不在循環內部創建命令?或者創建一個可以一次完成所有更新的SQL語句,並完全避免循環? –