Access数据库C＃查询问题

Question

Here is the background of my problem: I have a combobox that when users start typing, it should retrieve suggested items from a column in database table. The user starts inputing name and the program should suggest names by looking at both first and last names (database has separate tables for both )

Here is the code that I had:

        try{
            String temp = nameCBox.Text;
            AutoCompleteStringCollection namesSuggestion = new AutoCompleteStringCollection();
            OleDbConnection conn = new OleDbConnection("Provider=Microsoft.ACE.Oledb.12.0;Data Source=C:\\LogEntry\\LogEntry.accdb; Persist Security Info = False;");
            OleDbDataReader reader;
            conn.Open();
            String text2send = "Select Name from [Teachers] where FName like '" + temp + "' OR LName like '" + temp + "' Group by [Name]";
            OleDbCommand cmd = new OleDbCommand(text2send, conn);
            reader = cmd.ExecuteReader();
            if (reader.HasRows == true)
            {
                while (reader.Read())
                    namesSuggestion.Add(reader["temp"].ToString());
            }
            reader.Close();
            nameCBox.AutoCompleteCustomSource = namesSuggestion;

            conn.Close();
            }

errors: 1) I see no suggestions in the combo box 2) When I type in the combo box, it highlights the text and when I type something else again, it will write on the previous typed character.

Please Help desktopmaker

Answer 1

Since you are using Like operator, try to make the input between look like this : %input% To get something like :

Take a look at this , it may help

var sql = String.Format("Select Name from [Teachers] WHERE FName Like '%{0}%' OR LName Like '%{0}%'", temp);

Other points may be helpful about your current code :

• Use the using statement in your code, it dispose the resources, and for the Connection, it close it.

   using(var conn = new OleDbConnection("ConnectionStrong")) { //code } 

• The best, is to use a parameterized query Link

Answer 2

Erm

What's this doing

namesSuggestion.Add(reader["temp"].ToString()); 

reader is returning a column called Name..

I wouldunless the user is typing it in expect the search string to contain a wild card.

Eg Like 'John%' , or Like '%Smith' in standard sql, access uses * instead of % I seem to remember.

Oh and presumably you aren't worried about sql injection attacks??