combobox dropdown to display several tables from database

Question

I'm trying to get a combobox dropdown to display tables in datagridview from database, but I don't know how to do it, I can see example and explanation how to display only one table.

    private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
    {
        OleDbConnection conn = new OleDbConnection ();
        conn.ConnectionString = "Provider=Microsoft.ACE.OLEDB.4.0;Data     Source=|DataDirectory|\\Manager.accdb;Persist Security Info=True";
        OleDbCommand cmd = new OleDbCommand ("SELECT  Emplyee, Tasks, Projects from Manager");

        OleDbDataAdapter adapter = new OleDbDataAdapter(cmd);
        DataSet ds = new DataSet();
        adapter.Fill(dt, "Manager");  
    }

What's the problem? Errors? Is the dataset empty? Is the datagridview failing to bind? Or is it you aren't doing anything with the data adapter you filled? — Steve Wellens, Jun 15 '13 at 17:08

score 0 · Accepted Answer · edited May 23 '17 at 12:21

0

There is no provider named "Provider=Microsoft.ACE.OLEDB.4.0;", perhaps you want to use "Microsoft.ACE.OLEDB.12.0;"

Then, if you want to read all the data from the table names selected in the combobox then your code should be something like this

string conString = "Provider=Microsoft.ACE.OLEDB.12.0;" + 
                   "Data Source=|DataDirectory|\\Manager.accdb;" + 
                   "Persist Security Info=False";
string tableName = comboBox1.SelectedItem.ToString();
using(OleDbConnection conn = new OleDbConnection (conString))
using(OleDbCommand cmd = new OleDbCommand("SELECT * FROM [" + tableName + "]", conn))
{
    con.Open();
    using(OleDbDataAdapter adapter = new OleDbDataAdapter(cmd))
    {
        DataSet ds = new DataSet();
        adapter.Fill(ds, tableName);  
        dataGridView.DataSource = ds.Tables[0];
    }
}

Please, pay attention to the tablenames inserted in your combobox. Having the build of the sql command text made by string concatenation you have a very dangerous situation. Do not let the user inser these names, but select them yourself. If you have a malicious user it could mount an Sql Injection attack

edited May 23 '17 at 12:21

Community

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answered Jun 15 '13 at 17:09

Steve

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Thank you, but it's not displaying anything, do I have to bind with datagridview? – user2386687 Jun 15 '13 at 17:46
What kind of application? WinForms, WPF, ASP.NET. And did you see the names of the tables in the Output Window when debugging? – Steve Jun 15 '13 at 17:51
And by the way, what are you trying to display? – Steve Jun 15 '13 at 17:53
I'm trying to display tables from database to datagridview and I wanted to use combobox to select for eg task, instead of using a 4 buttons to display each table. – user2386687 Jun 15 '13 at 18:12
OK then you don't need to read the names of the tables. Now I will try to update my answer – Steve Jun 15 '13 at 18:45
I am back, Thank you Steve for your help, but it doesn't show anything. – user2386687 Jun 16 '13 at 14:57
dataGridView.AutoGenerateColumns = True ? – Steve Jun 16 '13 at 15:02

combobox dropdown to display several tables from database

1 Answers1