在sqlite3數據庫中插入參數時在vb.net中出錯

Question

在sqlite3數據庫中插入時出現錯誤'由於約束違反列轉移不唯一'而中止。這裏是我的代碼，有人可以幫我嗎？

Public Connection As SQLiteConnection 
Public Function Getconnection() As SQLiteConnection 
    Connection = New SQLiteConnection 
    Connection.ConnectionString = "Data Source=" + Application.StartupPath + "\POS.s3db; Version=3;" 
    Connection.Open() 
    GetConnection = Connection 
End Function 

Using cmd As New SQLiteCommand(strSQL,Connection) 
      cmd.CommandType = CommandType.Text 
      strSQL = "insert into tbltrans2 (transid,itemcode,flddate,itemname,qty,price,total,btw,btwper) values ('@tid',@itemcode,'@date','@itemname','@qty','@price','@total','@btw',@btwper)" 
      cmd.Parameters.AddWithValue("tid", txtTransId.Text) 
      cmd.Parameters.AddWithValue("date", txtDate.Text) 
      ''this is temp 

      For Each ls As ListViewItem In ListItems.Items 
       cmd.Parameters.AddWithValue("itemcode", ls.Tag) 
       cmd.Parameters.AddWithValue("itemname", ls.SubItems(0).Text) 
       cmd.Parameters.AddWithValue("qty", ls.SubItems(1).Text) 
       cmd.Parameters.AddWithValue("price", ls.SubItems(2).Text) 
       cmd.Parameters.AddWithValue("total", ls.SubItems(3).Text) 
       cmd.Parameters.AddWithValue("btw", (Double.Parse(ls.SubItems(5).Text)/100) * (Double.Parse(ls.SubItems(3).Text)).ToString("#,##0.00")) 
       cmd.Parameters.AddWithValue("btwper", Double.Parse(ls.SubItems(5).Text)) 
       cmd.ExecuteNonQuery() 
      Next ls 
     End Using 

Answer 1

貌似有上transid一個unique約束。這意味着您不能插入表中已存在的transid行。

嘗試輸入不同的transid或將transid設置爲auto-increment column，因此您根本不需要輸入它。