About how to use WHERE condition in JDBC

Question

Hello,
I met a problem when I wrote my jdbc program.
ResultSet rs1 = stmt1.executeQuery("select Ncategory from ncategory, whsites where whsites.Name = 'Heard and McDonald Islands'and whsites.Id=ncategory.IdWhsites");
ncategory and whsites are my two tables in my database. I try to select some data that conform to the WHERE conditions. Actually I want to input the name of
of whsites.Name, I defined
String sitename = "";
BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
          System.out.println("Please input the site name:");
          siteName = in.readLine();
Then I changed the above ResultSet sentence,
ResultSet rs1 = stmt1.executeQuery("select Ncategory from ncategory, whsites where whsites.Name = siteName and whsites.Id=ncategory.IdWhsites");
The program can be compiled. But I found the Resultset sentence has not been executed. How can I modify the executeQuery and make it work?

Answer 1

Hi,
Try using a prepared statement as shown below
PreparedStatement ps = connection.prepareStatement( "select Ncategory from ncategory, whsites where whsites.Name = ? and whsites.Id=ncategory.IdWhsites");
// Bind the airline code to the query
ps.setString(1,siteName );
result = ps.executeQuery();
Alternatively you could try the following too :
ResultSet rs1 = stmt1.executeQuery("select Ncategory from ncategory, whsites where whsites.Name = '"+siteName+"' and whsites.Id=ncategory.IdWhsites");