Question: I see the term “AFX” everywhere in the MFC source code.For example, “AFX_MSG_MAP”. What does it mean? Answer: I once asked this of Jeff Harbers, one of the original

Question: What is the best Netscape plug-in for viewing VRML files? Answer: I assume that because Netscape has chosen Live3d, formerly the WebFX browser from Paper Software, to be the

Question: What are the disadvantages of ODBC versus SQL? Answer: ODBC is a generic implementation, whereas native SQL is always optimized for the database server being used. Thus, if you

Question: Can I determine which employees have received a salary for a month that is more than twice the average salary in that month? I need to show:month_number, average salary,

Question: Is it possible to set indexes between tables in SQL expression? Answer: You can establish indexes on SQL tables, but SQL indexes do not create an implied relationship between

Question: What are the key features of the Moving Worlds proposal? Answer: Moving Worlds is VRML 2.0 proposal from a consortium of companies, formed by SGI, who are interested in

Question: I have a table with three columns: the firstcontains the name of the currency, thesecond contains the currency rate and the third contains the actual date when thecurrency rate

Question: Which rendering engines are used in VRML browsers and how do they affect my choice of browser? Answer: The library of functions that is used to create all the

Question: Is there a VRML browser most users prefer? If so, why? Answer: Well, if you’re Microsoft, then you may think that World View browser from Intervista Software is the

Question: What are the key features of IBM’s VRML 2.0 proposal? Answer: Researchers at IBM Japan have proposed a reactive virtual environment. No Web references to the proposal were available

Question: How can I ignore case when trying to SELECT allrecords that are LIKE a certain string variable? I have an employee’s name field in which the charactersare a combination

Question: I am trying to select data from three columns of a table listing all tables of a database. The table_name column is repeated with each separate column_namecolumn, hence the

Question: What VRML 2.0 sites are there now? Answer: Yes, there are products available that have been developed with the same aspirations as VRML 2.0 (i.e., simulation of the real

Question: What are the key features of Sun’s HoloWeb? Answer: Sun Laboratory’s HoloWeb proposal uses Java as an integrated real-time 3D animation scripting language. HoloWeb is a binary file format,

Question: [Joe Celko’s Phone Book Puzzle]You are trying to set up an office telephone directory and have the following tables: CREATE TABLE Employees (empid INTEGER PRIMARY KEY, firstname CHAR(20) NOT

Question: [Joe Celko’s Magazine Sales Puzzle]This one was posted on the Sybase forum of CompuServe by Keith McGregor in November of 1994.One of his end users came to him with

Question: [Joe Celko’s Hotel Rooms Puzzle]Ron Hiner put this question on the Watcom forum on CompuServe. He had a data conversion project where he needed to automatically assign some values

Question: [Joe Celko’s Promo Puzzle]Let’s assume that you have just gotten a job as the sales manager for a department store. Your database has the following two tables. One is

Question: Joe Celko’s Store Survey Puzzle]You are collecting statistical information stored by the quarter hour. What your customer wants is to get information by hour ? not on the hour.

Question: [Joe Celko’s Pension Plan Puzzle]Luke Tymowski, a Canadian programmer, posted an interesting problem on the MSAccess forum on CompuServe in 1994 November. He was working on a pension fund

Question: Joe Celko’s Playing the Ponies Puzzle]You have just become the database manager for Eddie Franco “the Doctor” Coddetti. He keeps records on horse races for statistical purposes and his

Question: Is there a site where VRML is being used to display information in a unique way? Answer: Yes, the most innovative site I have come across is that of

Question: [Joe Celko’s Tax Problem Puzzle]I got this one from Richard S. Romley, via CompuServe. We were engaged in a debate about Sybase’s old T-SQL versus ANSI/ISO SQL-92. I assume

Question: Are wildcards allowed when trying to matchthe contents of a textfield as in the following example? SELECT * FROM Database WHERE textfield = ‘B*’ Answer: Yes, but you’ll need

Question: I have a table that consists of numbers stored as characters.How can I sort them in numerical order? I can’t convert thisfield to numeric because some content is alpha

Question: [Joe Celko’s Work Order Puzzle]Cenk Ersoy asked this question on the Gupta Forum on CompuServe. He has a table that looks like this: CREATE TABLE Projects (workorder CHAR(5) NOT

Question: What is the difference between VRML 1.0 and 2.0? Answer: VRML 1.0 worlds are static environments in which you can move around and click on objects to link to

Question: What is the standard SQL-92 syntax for INSERT INTO? Answer: Be sure to check your product documentation for any variations! This is standard syntax, but not all products will

Question: Please explain Dynamic Worlds. Answer: “The Power of Dynamic Worlds” proposal from the German National Research Center (GMD) is based on an interaction model developed for collaborative distributed virtual

Question: I went to see one of the new VRML 2.0 sites, but only sawblackness. What is going on? Why won’t my VRML browserwork with the new version? Answer: Just