How prevent duplicates in combobox in windowsapplication using c#?

Question

how to prevent duplicates in combobox in windowsapplication using c#?

Satyapriya Nayak · Answer

Hi Srinivas, SELECT columnname FROM tablename GROUP BY columnname Then bind the query to combobox as con.Open(); str = "select sname from student GROUP BY sname"; com = new SqlCommand(str, con); SqlDataReader reader = com.ExecuteReader(); while (reader.Read()) { comboBox1.Items.Add(reader["sname"]); } reader.Close(); con.Close(); Thanks

Vulpes · Answer

If you're not binding to a DataTable but to an array or List, then you can remove duplicates by passing it to a HashSet first. For example: string[] names= {"srinivas", "mangesh", "vilas", "vulpes", "srinivas"}; HashSet hs = new HashSet (names); names = hs.ToArray(); comboBox1.DataSource = names; // duplicate "srinivas" removed

Vilas Gite · Answer

Hi Srinivas! You can bind data from store procedure to combobox with primary key column table. Thanks! ----------------------------------------------------------------------- If this reply helps your post…then check " This is correct answer"

mangesh shelar · Answer

You can Use Distinct in the Query used to get the data for the combobox.