JDBC - a little bit more

*   now, we can query a database using JDBC

    *   how about updating or changing a
        database?

    *   how about if you have SEVERAL things
        to do in a row?

    *   [maybe] how you can ask questions
        ABOUT a database using JDBC

*   to UPDATE or otherwise change a database,
    you'll use the Statement method
    executeUpdate, and note that it returns an int

    *   see example AddToLog.java

*   PreparedStatement - subclass of Statement class

    *   it is FASTER when doing several similar actions
        in a row than having a separate Statement for each

    *   it CAN be safer, because it helps reduce the
        chances of some kinds of SQL injection

    *   PreparedStatement myPStmt =
           con.prepareStatement(
               "insert into log_table " +
               "values " +
               "(?, sysdate)");

        *   you give it the command string AT   
            prepared-statement-creation time, WITH
	    ? for each value you want to set later

        *   you SET each ? using
	    a set* (setString, setDouble, setDate, etc.)
            with the position of the question mark (1, 2, ...)
	    and the desired value for that question mark

	    myPStmt.setString(1, "moo");

        *   and, once you've set all the ?s,

	    run either executeQuery or executeUpdate
	    (depending on the kind of SQL statement)
	    with NO arguments)

    *   demo'd in AddManyToLog.java

        (and NOTE: you CAN and should use PreparedStatement
	instances for select statements when appropriate,
	also!)