How To Avoid Repeat Data In Dropdownlist

Question

User-807418713 posted

Hello

I Used This Code In My Page https://forums.asp.net/post/6265870.aspx

I Want DropDownList1 And DropDownList2 Make Distinct Name, It Showing

For example DropDownList1

ABCD

ABCD

ABCD

But I Want Only One Time

ABCD

KLMN

VWXY

How To Make Value Distinct, Thank You

Answer 1

User475983607 posted

Use DISTINCT.

SELECT DISTINCT Supplier FROM Personal_Details;

https://www.w3schools.com/sql/sql_distinct.asp

Answer 2

User-719153870 posted

Hi Gopi.MCA,

In your method of binding DropDownList1 data, please use the following SQL statements:

select distinct Supplier from Personal_Details 

In the aspx.cs, please refer to below codes:

 [WebMethod]
        public static string DropDownList1Bind()
        {
            List<PersonalDetails> details = new List<PersonalDetails>();
            SqlConnection conn = new SqlConnection("Data Source=.;Initial Catalog=Education;Integrated Security=True;");
            SqlCommand command = new SqlCommand("SELECT distinct Supplier FROM Personal_Details;", conn);
            conn.Open();
            SqlDataReader reader = command.ExecuteReader();
            if (reader.HasRows)
            {
                while (reader.Read())
                {
                    PersonalDetails detail = new PersonalDetails();
                    detail.Supplier = (string)reader["Supplier"];
                    details.Add(detail);
                }
                reader.Close();
            }
            conn.Close();
            JavaScriptSerializer jss = new JavaScriptSerializer();
            string myJson = jss.Serialize(details);
            return myJson;
        }

Here's my result of work demo:

Best Regard,

Yang Shen