vb.net插入查詢錯誤

Question

變量Itemtext已被聲明。爲什麼這個錯誤？

Try 
     conn = New SqlConnection(connString) 
     conn.Open() 
     Dim i As Integer = 0 
     Using cmd As New SqlCommand() 
      For Each c In item 
       cmd.Connection = conn 
       cmd.CommandType = CommandType.Text 
       cmd.CommandText = "INSERT INTO tblItems(Item,Numberof) Values (@Itemtext,@Numberof)" 
       cmd.Parameters.AddWithValue("@Itemtext", c) 
       cmd.Parameters.AddWithValue("@Numberof", num(i)) 
       cmd.ExecuteNonQuery() 
       i = i + 1 
      Next 
     End Using 

Answer 1

因爲你每次加參數的循環

Using cmd As New SqlCommand() 
     cmd.Connection = conn 
     cmd.CommandType = CommandType.Text 
     cmd.CommandText = "INSERT INTO tblItems(Item,Numberof) Values (@Itemtext,@Numberof)" 
     Dim ItemParameter As SqlParameter = cmd.Parameters.Add("@Itemtext",SqlDbType.VarChar) 
     Dim NumberParameter As SqlParameter = cmd.Parameters.Add("@Numberof", SqlDbType.Int) 
     For Each c In item 
      ItemParameter.Value = c 
      NumberParameter.Value = num(i) 
      cmd.ExecuteNonQuery() 
      i = i + 1 
     Next 
    End Using