October 2, 1998

Question: I need to write a query that selects the maximus sum for a group from a list like the one below. Type ValueA 100B 200C 300A 300B 100C 342 The result should be C, 642. I tried “group by,” but I could only get the sums. Answer: You must

Question: I have a table, called bugs. I have an insert trigger on the bugs table that generates a unique id, called bug_id. When I perform an insert into bugs, it returns the bug_id it just assigned to that record. I am writing a stored procedure called doit that will

Question: I’m trying to work on the basics of event handling. I found it easy to set one label and have the scrollbar change the value of the label. I added a few more scrollbars, each with a separate label. When I move any scrollbar, only the first label value

Question: How do I add a JButton to the cells of a JTable? Answer: Using the Swing JTable class can become a sticky business when you want to customize it to your specific needs. First you must become familiar with how the JTable class is organized. Individual cells are rendered

Question: For what uses can the Graphics.create() method be used? Answer: There will be cases where you want to make a copy of a Graphics context and make some alterations to it (for example, change the foreground or background color) without losing the original Graphics context. Also, there will be

Question: How can you make a canvas nonresizable? The canvas automatically resizes when the frame is resized. Answer: The default layout manager for java.awt.Frame is BorderLayout. BorderLayout will expand the components of its associated container along the regions to which they are attached. For example, a component added to the

Question: I am a beginner in SQL and can’t figure out how to do this: I have two tables with three fields in the row of table1 referencing a master table in an n-1 relation as follows: JobMast ContractorMast======= ==============JobID ContrIDJobDescription —–1> ContrName GenContractorID n ———/ | |ElecContractorID n ———–/

Question: On a Windows NT box with multiple processors, will a multithreaded Java application get split between the processors automatically? Answer: This depends on the version and vendor of theJVM you are running. The Microsoft SDK for Javauses native NT threads to implement Java threads.These threads are scheduled by the

Question: I have a frame with a few textfields on it. How can I set the focus to the first textfield? Is there something like setFocus? Answer: A component can obtain the input focus by invoking requestFocus(), which is defined in java.awt.Component.