avoiding replicated items from a combobox in vb

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i am having a problem while calling value from a column to a combobox. i am using mysql with a table emp having employee detail id,name,address,contact

i am using the code

VB

cnn = New MySqlConnection
cnn.ConnectionString = ("server=localhost;userid=root;password=root;database=hello")

Try
            cnn.Open()
            Dim query As String
            query = "SELECT * from hello.emp"
            cmd = New MySqlCommand(query, cnn)
            rdr9 = cmd.ExecuteReader
            While rdr9.Read
                Dim adr = rdr9.GetString("address")
                ComboBox1.Items.Add(adr)
            End While
            cnn.Close()
        Catch ex As MySqlException
            MessageBox.Show(ex.Message)
        Finally
            cnn.Dispose()
        End Try

this code shows the address in the combobox but if there are 8 entries of same address it shows 8 items of same name like:

calcutta
delhi
delhi
delhi
calcutta
delhi

Posted 9-Jul-14 4:21am

the challanger

Updated 9-Jul-14 4:22am

CHill60

v2

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nilesh sawardekar 12-Jul-14 5:14am

"but is there any other way to call first and remove selected items"
whats this mean?explain in brief

3 solutions

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CHill60 · Answer 1 · 2014-07-09T04:24:00

Solution 1

Try

SQL

query = "SELECT distinct address from hello.emp"

Posted 9-Jul-14 4:24am

CHill60

the challanger · Answer 2 · 2014-07-09T04:45:00

Solution 2

query = "SELECT DISTINCT address from hello.emp" & ComboBox1.Text & ""
i used the above code while calling the items and it worked

but is there any other way to call first and remove selected items

Posted 9-Jul-14 4:45am

the challanger

Comments

CHill60 9-Jul-14 19:08pm

You're lucky I spotted this... don't post solutions to respond ... use either the "Have a Question or Comment?" or "Reply" link as appropriate.
Yes - in theory you "could" populate the comboBox and then start removing items - but that would be the wrong approach. The solution I've suggested works well, does exactly what you need and is efficient. Not sure where your "& ComboBox1.Text & "" has come from... don't do that ... use parameterised queries instead ... see give-me-parameterized-sql-or-give-me-death/[^]

basurajkumbhar · Answer 3 · 2014-07-11T03:55:00

Solution 3

Hi You can use the Distinct fro this ..

SQL

query = "SELECT distinct address from hello.emp"

Posted 11-Jul-14 3:55am

basurajkumbhar

Comments

[no name] 11-Jul-14 10:28am

Copying and pasting someone else's solution as if it were your own is so not cool. And it's abuse.