保存在文本框中以逗号分隔的唯一值

Question

我有一个要求，我将在文本框中保存逗号分隔的值，但在保存时我想检查值应该是不同的。有人可以帮助我如何实现它

注意点：- 当保存另一个已经保存的具有相同值的记录时，会抛出异常记录已经存在，但是对于相同的记录，它正在保存重复值。 enter image description here

Answer 1

好的，一个文本然后说一个按钮。这个标记：

        <asp:TextBox ID="TextBox1" runat="server" Height="20px" Width="255px"></asp:TextBox>
        <br />
        <asp:Label ID="Label1" runat="server" ForeColor="Red" Text=""></asp:Label>
        <br />
        <asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="Submit" />

然后是我们的代码：

    protected void Button1_Click(object sender, EventArgs e)
    {
        Label1.Text = "";
        if (TextBox1.Text != "")
        {
            string s = TextBox1.Text.Replace(" ", "");
            string[] nItems = s.Split(',');
            // make sure no duplications in input eg: ABC,DEF,ABC
            List<string> MyCheckList = new List<string>();
            foreach (string sCheck in nItems)
            {
                if (MyCheckList.Contains(sCheck))
                {
                    Label1.Text = "Reapted token not allowed";
                    return;
                }
                else
                    MyCheckList.Add(sCheck);
            }
            // ok, no tags repeat in user input,
            // sort the items, and then check if in database.
            MyCheckList.Sort();
            s = string.Join(",",MyCheckList);
            // check database for this value
            string strSQL = "SELECT COUNT(*) FROM Table1 WHERE Twitter_HashTags = @Tags";
            using (SqlConnection conn = new SqlConnection(Properties.Settings.Default.TEST4))
            {
                using (SqlCommand cmdSQL = new SqlCommand(strSQL, conn))
                {
                    cmdSQL.Parameters.Add("@Tags", SqlDbType.NVarChar).Value = s;
                    conn.Open();
                    int? FoundCount = cmdSQL.ExecuteScalar() as int?;
                    if (FoundCount > 0)
                    {
                        Label1.Text = "Those tags already exist in database";
                        return;
                    }
                    else
                    {
                        // not in database - add it  (paramter already set)
                        cmdSQL.CommandText = "INSERT INTO Table1 (Twitter_HashTags) VALUES(@Tags)";
                        cmdSQL.ExecuteNonQuery();  
                    }
                }
            }
            // we are good here - update text box with sorted tags, and spaces removed
            TextBox1.Text = s;
        }
    }