Asp. NET to determine whether the database has the same data

To determine whether the database has the same data, is often used in a function, in addition to select, there are other methods? Here's a little bit of advice!

(UrlAdd.aspx.cs) Sample code in

Determine if the URL exists if
(Navigation.beurl (URL))
{
sperror.　　　　　　　　innertext = "URL you already have a database!";
return;
}　　

Query whether the Web site has a database

public static bool Beurl (string url)
{
String sql = ' Select COUNT (1) from [Navurl] WHERE [url]= @url '; 
  SqlParameter parameters = new SqlParameter ("@url", sqldbtype.varchar,50);
Parameters.　　　　　　Value = URL;
return dbhelper.exists (SQL, parameters);
}