我有一個 Windows 應(yīng)用程序，它調(diào)用服務(wù)然后寫入數(shù)據(jù)庫。在寫結(jié)果之前，我刪除了舊數(shù)據(jù)。Windows 應(yīng)用程序使用每 5 分鐘運(yùn)行一次的計(jì)時器調(diào)用該服務(wù)。問題是：即使我使用刪除，代碼也不會刪除記錄。如果我不使用計(jì)時器調(diào)用它，它就可以工作。我使用事務(wù)，使用 EF 不起作用。它仍然不刪除記錄。 static void Main(string[] args) { //////Start Timer Timer timer = new Timer(); timer.Interval = 5 * 60 * 1000; // converts ms to minutes timer.Elapsed += new ElapsedEventHandler(InsertRecords); timer.Enabled = true; timerFired.WaitOne(); } public void InsertRecords() { using (SqlConnection connection = new SqlConnection(connectionstr)) { connection.Open(); // Delete old entries SqlTransaction trans = connection.BeginTransaction(); string sql = "Delete from PhilaMethod "; SqlCommand cmd = new SqlCommand(sql, connection, trans); trans.Commit(); connection.Close(); } var conn = connectionstr; string SQL1 = ""; foreach (PhilaMethod phila in phila2) { SQL1 += "INSERT INTO PhilaMethod(Name,PS1,PS2,RSI1,) values ('" + phila.Name + "','"+phila.PS1+"','"+phila.PS2+"','"+phila.RSI1+"','"+phila.RSI2+"'); "; } string SQL2 = "Delete from philamethod"; using (SqlConnection connection = new SqlConnection(conn)) { connection.Open(); SqlTransaction sqlTran = connection.BeginTransaction(); SqlCommand command = connection.CreateCommand(); command.Transaction = sqlTran; try { command.CommandText = SQL2; int rowsAffected = command.ExecuteNonQuery(); if(rowsAffected >= 0) { command.CommandText = SQL2; int rowsAffected2 = command.ExecuteNonQuery(); if(rowsAffected2 == 0) { command.CommandText = SQL1; rowsAffected += command.ExecuteNonQuery(); } }
2 回答
慕容708150
TA貢獻(xiàn)1831條經(jīng)驗(yàn) 獲得超4個贊
您需要執(zhí)行命令。
using (SqlConnection connection = new SqlConnection(connectionstr))
{
connection.Open();
// Delete old entries
SqlTransaction trans = connection.BeginTransaction();
string sql = "Delete from PhilaMethod ";
SqlCommand cmd = new SqlCommand(sql, connection, trans);
cmd.ExecuteNonQuery(); // <--- added this
trans.Commit();
connection.Close();
}
元芳怎么了
TA貢獻(xiàn)1798條經(jīng)驗(yàn) 獲得超7個贊
您的代碼存在一些問題。您應(yīng)該始終處理一次性物品。通過調(diào)用Dispose()或使用using {}塊，這是首選方式。
1.）您沒有處理您的 SqlCommand 對象您應(yīng)該將它們包裝在 using 語句中以避免此錯誤和可能的內(nèi)存泄漏。
2.) 您沒有處理您的 SqlTransaction 對象您應(yīng)該始終將其包裝在 using 語句中以避免可能的內(nèi)存泄漏。
3.）像其他人已經(jīng)寫過你必須執(zhí)行一個命令。;)
using (SqlConnection connection = new SqlConnection(connectionstr))
{
connection.Open();
// Delete old entries
SqlTransaction trans = connection.BeginTransaction();
string sql = "Delete from PhilaMethod ";
SqlCommand cmd = new SqlCommand(sql, connection, trans);
trans.Commit();
connection.Close();
}
在此代碼中，缺少執(zhí)行。;) 所以你的代碼應(yīng)該如下所示。（未測試）
using (SqlConnection connection = new SqlConnection(connectionstr))
{
connection.Open();
// Delete old entries
using (SqlTransaction trans = connection.BeginTransaction())
{
string sql = "Delete from PhilaMethod ";
using (SqlCommand cmd = new SqlCommand(sql, connection, trans))
{
cmd.ExecuteNonQuery(); // or whatever method you need
}
trans.Commit();
}
connection.Close();
}
- 2 回答
- 0 關(guān)注
- 150 瀏覽
添加回答
舉報(bào)
0/150
提交
取消