bind gridview with datasource gives me invalid column

I want to bind my gridview with my SQL query that is my data source. I tried, but it gives me an error. I'm using my login ID as a where clause in my select query. Here is my code:

string user;
protected void Page_Load(object sender, EventArgs e)
{
   Label1.Text = Session["unm"].ToString();
   user = Label1.Text;

   Response.Write(user);
   string queryString = "Select * from FILE_INFO WHERE ALLOCATED_TO = " + user + "";
   DataSet ds = GetData(queryString);
   if (ds.Tables.Count > 0)
   {
      GridView1.DataSource = ds;
      GridView1.DataBind();
   }
   else
   {
      Response.Write("Unable to connect to th开发者_如何学Pythone database");
   }
}
DataSet GetData(String queryString)
{

string connectionString = @"Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\Database.mdf;Integrated Security=True;User Instance=True";

         DataSet ds = new DataSet();

         SqlConnection con = new SqlConnection(connectionString);
         SqlDataAdapter adapter = new SqlDataAdapter(queryString, con);

         adapter.Fill(ds);
         return ds;
    }

It gives me an Invalid Column exception at this line:

adapter.Fill(ds);

Could someone tell me where I'm going wrong?

problem is this statement and you missed single quote for string value and replace this statement with this one...

string queryString = "Select * from FILE_INFO WHERE ALLOCATED_TO = '" + user + "'";

Verify that your datagrid has "AutogenerateColumns" property set to "true"