CODEWITHSUNDEEP
c#sql.net
tsobw
tsobw

Reputation: 15

Show SQL results in ListBox

I would like to show a query in a listbox. Here is what I have to far:

private void PopulatePeople()
{

    string query = "SELECT Name FROM People WHERE KnownFrom = KSOK";//@KnownFrom";

    using (connection = new SqlConnection(connectionString))
    using (SqlCommand command = new SqlCommand(query, connection))
    using (SqlDataAdapter adapter = new SqlDataAdapter(command))
    {
        //command.Parameters.AddWithValue("@KnownFrom", listBox1.SelectedItem);

        DataTable PeopleDT = new DataTable();
        adapter.Fill(PeopleDT);

        listBox2.DisplayMember = "Name";//+"Surname";
        //listBox2.ValueMember = "Id";
        listBox2.DataSource = PeopleDT;
    }
}

At this point it says, that there is no column KSOK. What am I doing wrong?

Upvotes: 0

Views: 177

Answers (3)

user4628565
user4628565

Reputation:

try to change,

string query = "SELECT Name FROM People WHERE KnownFrom = KSOK";

to

string query = "SELECT Name FROM People WHERE KnownFrom = 'KSOK'";

When you have string literal as part of your queries, they should be wrapped by single quotes '.

Upvotes: 0

Vahlkron
Vahlkron

Reputation: 464

If you would like to use Parameters, like you had commented out, you can do the following (using ListBox2.SelectedItem.ToString() to get the value from the UI):

command.Parameters.AddWithValue("@KnownFrom", ListBox2.SelectedItem.ToString()); //Edited to use value from UI.

Then, add the @ variable to your query string for KSOK:

string query = "SELECT Name FROM People WHERE KnownFrom = @KnownFrom";

Upvotes: 1

Douglas
Douglas

Reputation: 54877

If KSOK is the string you are searching for, then you need to quote it:

string query = "SELECT Name FROM People WHERE KnownFrom = 'KSOK'"
                                                       // ^    ^ quotes

Upvotes: 4

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