Question

I’m not sure why, but for some reason, the following code skips the else condition. I’ve tried just about everything I can think of, including switching the code blocks, but it still skips the else part. Basically, I want this method to return String temp = "no" if String docID that is passed to the method is not found in the FILESTATUS database, and String temp = "yes" if it is found.

static String checkDocID(String docID)
{
    String temp = null;

    System.out.println("Checking if data already exists in database...");
    try
    {
        Main.stmt = Main.con.createStatement();
        String command = "SELECT * FROM FILESTATUS WHERE ID='" + docID + "'";
        ResultSet queryResult = Main.stmt.executeQuery(command);
        if (!queryResult.next())
        {
            temp = "no";
        }
        else
        {
            while (queryResult.next())
            {
                String result = queryResult.getString("ID");
                if (result.equals(docID))
                {
                    temp = "yes";
                    break;
                }
            }
        }
        Main.stmt.close();
    }
    catch (Exception ex) {ex.printStackTrace();}
    return temp;
}

Thanks!

Answer 1

Because you end up calling queryResult.next() in the “if” and again in the while, you’re skipping the first result. If there is only one result, the while loop will never execute.

If I can make a couple of suggestions:

• Use bound variables in a PreparedStatement rather than putting “docID” in the query string
• Don’t test result.equals(docID) since the query already assured that.
• prefer boolean to String “yes” or “no”
• set the result to “no” or false, then set it to “yes” or true in the loop. The extra assignment is probably faster than the extra test, plus you can skip the do{}while which most people find harder to read.