從數據庫中刪除重複項

Question

我有以下代碼用於從文件讀取並填充我的數據庫。一切工作正常，但所有記錄都插入兩次。

OleDbCommand c = new OleDbCommand(); 
c.Connection = GetConnection(); 
c.CommandText = 
    @"CREATE TABLE patients (
     patientid AUTOINCREMENT PRIMARY KEY, 
     firstlastname CHAR(50), 
     birthdate CHAR(50), 
     birthplace CHAR(50), 
     gender CHAR(1), 
     bloodtype CHAR(50), 
     telnum CHAR(50), 
     address CHAR(255) 
    )"; 
c.ExecuteNonQuery(); 

string info = ""; 
string name = ""; 
string date = ""; 
string place = ""; 
string blood = ""; 
string num = ""; 
string address = ""; 
//Read from file and insert values to patient table 
StreamReader myReader = new StreamReader("myPath/patient.txt"); 
while (true) 
{ 
    info = myReader.ReadLine(); 
    if (info == null) break; 

    if (info.Trim() != String.Empty) 
    { 
     string[] words = info.Split(','); 
     if (words.Length == 6) 
     { 
      name = words[0].Trim(); 
      date = words[1].Trim(); 
      place = words[2]; 
      blood = words[3]; 
      num = words[4]; 
      address = words[5]; 
     } 
    } 

    string cmdText = "INSERT INTO patients (" + 
     "firstlastname, birthdate, birthplace, bloodtype, telnum, address) " + 
     "VALUES (?,?,?,?,?,?)"; 

    using (OleDbConnection cn = GetConnection()) 
    { 

     using (OleDbCommand cmd = new OleDbCommand(cmdText, cn)) 
     { 
      cmd.Parameters.AddWithValue("name", name); 
      cmd.Parameters.AddWithValue("date", date); 
      cmd.Parameters.AddWithValue("place", place); 
      cmd.Parameters.AddWithValue("blood", blood); 
      cmd.Parameters.AddWithValue("num", num); 
      cmd.Parameters.AddWithValue("address", address); 
      cmd.ExecuteNonQuery(); 
     } 
    } 


} 

我注意到，行 if (info.Trim() != String.Empty)

返回「假」，所以記錄插入兩次，但不知道如何解決這個問題每個其他時間。

我該如何消除這些重複？ 感謝

編輯：文件內容顯示等名稱，日期，城市，血型，移動NUM和地址：

Mehtap塞利姆，1985年11月6日，凱里尼亞，FBRh +，05617584509，Yasemin聖編號：48 Edremit Kyrenia KKTC

Answer 1

它看起來像是你的代碼結構仍然允許寫入數據庫，即使條件語句是錯誤的，並且由於數據仍然在你的變量中，再次。嘗試將數據庫寫入封閉到相同的條件。至於爲什麼它每隔一段時間就會出現錯誤，我們需要查看文件的內容。

即

if (info.Trim() != String.Empty) 
{ 
    string[] words = info.Split(','); 
    if (words.Length == 6) 
    { 
     name = words[0].Trim(); 
     date = words[1].Trim(); 
     place = words[2]; 
     blood = words[3]; 
     num = words[4]; 
     address = words[5]; 
    } 


    string cmdText = "INSERT INTO patients (" + 
     "firstlastname, birthdate, birthplace, bloodtype, telnum, address) " + 
     "VALUES (?,?,?,?,?,?)"; 

    using (OleDbConnection cn = GetConnection()) 
    { 
     using (OleDbCommand cmd = new OleDbCommand(cmdText, cn)) 
     { 
      cmd.Parameters.AddWithValue("name", name); 
      cmd.Parameters.AddWithValue("date", date); 
      cmd.Parameters.AddWithValue("place", place); 
      cmd.Parameters.AddWithValue("blood", blood); 
      cmd.Parameters.AddWithValue("num", num); 
      cmd.Parameters.AddWithValue("address", address); 
      cmd.ExecuteNonQuery(); 
     } 
    } 
}