SQL add string as a parameter
<pre><code>//cmd.CommandText = @"select MaKH from KHACHHANG where HoTenKH='a'";
cmd.CommandText = @"select MaKH from KHACHHANG where HoTenKH=$tenKH";
cmd.Parameters.Add(new SQLiteParameter("$tenKH", tenKH));
</code></pre>

<p>The comment line works, cmd is a DbCommand, I've tried </p>

<pre><code>cmd.CommandText = @"select MaKH from KHACHHANG where HoTenKH='$tenKH'";
</code></pre>

<p>But it doesn't work neither.</p>
