Question

我遇到了一个问题，在我的客户信息表中有客户ID，请联系no＆amp;两个或更多客户的电子邮件地址不应该相同。我还将custmomerid设置为主键。 Plz让我知道如何获取警告消息框，添加到数据库时已存在相同的数据......

private void button1_Click(object sender, EventArgs e)
    {

        SqlConnection con = new SqlConnection();
        con.ConnectionString = @"Data Source=HP\SQLEXPRESS100;Database=CD_Gallery;Integrated Security=true";
        con.Open();
        if (con.State == System.Data.ConnectionState.Open)
        {
            SqlCommand cmd = new SqlCommand("insert into Customer_Info values('" + Custid.Text.ToString() + "','" + fname.Text.ToString() + "','" + lname.Text.ToString() + "','" + landmark.Text.ToString() + "','" + address.Text.ToString() + "','" + contact.Text.ToString() + "','" + email.Text.ToString() + "','" + dateTimePicker1.Text.ToString() + "','" + deposite.Text.ToString() + "')", con);
            cmd.Connection = con;
            cmd.CommandType = System.Data.CommandType.Text;
            int a = cmd.ExecuteNonQuery();
            if (a > 0)
            {
                MessageBox.Show("You Have Successfully Inserted");
                this.customer_InfoTableAdapter1.Fill(this.cD_GalleryDataSet7Cust_add.Customer_Info);
                Custid.Text = "";
                fname.Text = "";
                lname.Text = "";
                address.Text = "";
                contact.Text = "";
                email.Text = "";
                landmark.Text = "";
                deposite.Text = "";
            }
        }
    }

Answer 1

如果我理解正确，您需要防止在customerID，contactNo和Email上重复输入。最直接的答案是将主键放在所有三列上。这会在添加已经存在的记录时抛出DuplicateRecord异常，你应该正确捕获它。

另一种方法是检入查询（使用执行标量）：

＆＃34; IF EXISTS（从customer_info中选择1，其中customerID = ...和   contactNo = ...和email = ...）

BEGIN选择-1返回结束

插入Customer_Info值（＆＃39; ..........（您的查询）＆＃34;

希望有所帮助

用于检查表列中存在的相同数据的代码

1 个答案: