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The Latest

Finding Data Based on Contents of Multiple Columns

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

VRML displaying information on a Web site

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

Tax Problem Puzzle

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

Wildcard Searches in SQL

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

Sorting “Codes” within a Column

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

Solving Multiple Conditions Within a Group

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

INSERT INTO Syntax

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

What is GMD’s Dynamic Worlds proposal about?

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

Why won’t my VRML browser work with 2.0?

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

What is Microsoft’s Active VRML proposal about?

Question: What are the key features of Active VRML? Answer: Microsoft’s Active VRML, is a proposal built on top Microsoft’s Direct X suite of graphics/multimedia APIs, and also incorporates Microsoft’s

How compatible are VRML browsers?

Question: If I make a VRML page, can it be read by any browser? Answer: The original idea behind VRML 1.0 was that any VRML scene should be viewable using

Finding the Top n Within a Group

Question: [Joe Celko’s Best Salesmen by Territory Puzzle]Martin Tillinger posted this problem on the MSAccess forum of CompuServe. How do you get the top three salesmen in each territory, given

How can I create VRML pages?

Question: What can I use to produce VRML, or can I write it like HTML? Answer: It is possible to write VRML as a purely text-based language, using a regular

Finding the Greatest Lower Bound

Question: [Joe Celko’s Sales Gaps Puzzle]Given a table “sales” and a column “saledate” and “customer,” is there a way to get the average number of days between sales dates for

Calculating Running Totals

Question: [Joe Celko’s Quantity on Hand Puzzle]You are now the guy in charge of the company inventory. You get requisitions that tell how many widgets people are putting into a

CHECK Constraint To Avoid Overlapping Data

Question: [Joe Celko’s Reservations Puzzle]Since I spend a lot of time this column talking about problems with the order of execution of SQL statements, it is only fair that I

What is VRML?

Question: I’ve heard a lot about VRML, but don’t know what it is. Please explain. Answer: VRML (Virtual Reality Markup Language) is a method for sending 3D data across the

Finding Two Equal Sets of Data

Question: [Joe Celko’s Equal Sets Puzzle]Set theory has two symbols for subsets. One is a “horseshoe” on its side, which means that set A is contained within set B and

Dataflow Diagrams

Question: [Joe Celko’s Dataflow Diagrams Puzzle]Tom Bragg posted a version of this problem on the CASE Forum on CompuServe. You have a table of dataflow diagrams (DFDs), which has the

Pivoting Table Data — Horizontal Display

Question: [Joe Celko’s Milestones Puzzle]This puzzle, in a little different form, came from Brian Young. His system tracks a series of dates (milestones) for each particular type of service (tos)

Finding Exactly Two of Three — Conditions

Question: We are putting together a book with contributions from many Anthologies (identified by their contrnum). We want to find all Anthologies thathave articles in exactly two out of three

Finding Unique Data

Question: How would I change the following statement to yieldonly unique values? select * FROM WEBDBASE where ST = ‘#State#’ AND #SPECIALTY# = ‘x’; Answer: You can’t get unique values

Pattern Matching

Question: How can I use SQL to specify a query like the example below: select * from mytable where column like ‘a[bc]’This should match both “ab” and “ac” but not

GROUP BY: Sorting with an Additional Column

Question: How do I arrange to sort within a GROUP BY clauserather than over the complete result set, e.g. L0 PDV …… L90 PDV …… L180 PDV …… L270 PDV

Matching Employees’ Skills with Jobs

Question: [Joe Celko’s Employment Agency Puzzle]You are running an employment agency that has requests for jobs and applications from candidates. Both of these forms include a list of the skills

Calculating Hourly Billings

Question: [Joe Celko’s Consultants Puzzle]Brian K. Buckley posted a version of the following problem on the PowerSoft CompuServe forum in the WATCOM SQL section in 1994 November requesting assistance. He

Compare Budget and Actual Tables

Question: [Joe Celko’s Budget Versus Actual Puzzle]C. Conrad Cady posted a simple SQL problem on the CompuServe Gupta Forum. He has two tables, Budgeted and Actual, which describe how a