CODEWITHSUNDEEP
c#sql
Salik47
Salik47

Reputation: 179

Code for checking the same data present in table column

I am facing a problem, that in my customer info table the customer id, contact no & E-mail address should not be same for two or more customers.I also have set custmomerid as the primary key. Plz let me know how to get the warning message box for that, there is the same data already present while adding to database......

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 = "";
            }
        }
    }

Upvotes: 0

Views: 557

Answers (1)

TamerM
TamerM

Reputation: 762

If i understood correctly, you need to prevent duplicate entries on customerID, contactNo and Email. The most straight forward answer is put the primary key on all three columns. This would throw a DuplicateRecord Exception when adding a record that already exists and you should properly catch it.

Another way is to check in the query (with execute scalar):

"IF EXISTS(select 1 from customer_info where customerID = ... and contactNo = ... and email = ...)

BEGIN select -1 RETURN END

insert into Customer_Info values('.......... (your query)"

Hope that helps

Upvotes: 2

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