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The LA Fox Developer Newsletter
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August 1997
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VFP (and FP2.x before it) gives the developer a lot of control over the environment at run time. This includes commands that lets you set basic things like what century we are in (SET CENTURY TO), different sethngs related to localization (e.g. SET DATE TO or SET CURRENCY TO), stuff that affect searching and string matching (like SET ANSI, SET COLLATE), and stuff that affects the way VFP works in general (like SET
MULTI LOCKS, SET EXCLUSIVE).
It is very worthwhile for any beginner VFP developer to check the SET section of the VFP help file to find what all these commands can do for you. While I am at it, another section of the help file worth reading is the SYSO section, there are many functions there that otherwise are not part of the language, which lets you do some interesting stuff. While this does not fall under the subject of this article I’ll just mention 2 or 3 interesting SYS functions. For example sys(3O54) lets you see the optimization level of your SELECT statements, SYS(1270) will give you a reference to the object under the mouse or at a specific X/ Y, and SYS(2333) is needed when you want to use an OCX created in VB5.
Now returning to our business, many of the different SETtings will not change throughout the application, and indeed a lot of FP2.x programs started with a bunch of SET commands in the main program like SET TALK OFF, SET EXCLUSiVE OFF etc.
One of the new concepts added in VFP is the private datasession, this brings a lot of good and saves some programming effort. For example it is now very easy to have the same form open twice each time with a different record, in earlier versions you had to do some programming to make this happen. However this prevents you from using the same technique described above of setting all your SETs in the main program. Because many of the SET commands are scoped to the datasession, they are reset to default values for each instance of a form and have to be set manually. The table below lists the SET commands that are scoped to the datasession:
UNIQUE
Note that to set them to the value you want before any table is loaded, you have to set them in the BeforeOpenTables event of the DataEnvironment. If you don’t use a DataEnvironemnt, or
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The LA Fox Developer's Group has entered into an agreement with Macmillan Computer Publishing. LA Fox members can now purchase all Macmillan Computer Publishing titles at a discount of 30% off retail pricing.
Macmillan owns the following publishers:
Que
New Riders Press
The Waite Group
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Que Education & Training
Macmillan Technical Publishing
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With all these publishers and over 40% market share, Macmillan has the best books for computer technology.
To take advantage of this offer, you must be a member-in-good- standing (read current and paid-up) and have a credit card. You can receive our special account number and the 800 access number by calling me at 800/499-6237 or 714/375-3300, ore- mailing me at CompuServe (72723,3422) or brlee@earthlink.net.
The online update document for Mastering Visual FoxPro is now available. This document, designed to be used with the Mastering Visual FoxPro CD-ROM-based training product, covers the new features and differences between Visual FoxPro 3.0 and Visual FoxPro 5.0. Now you can use the advanced features of the Visual FoxPro Web site to quickly explore the contents of this useful learning tool and shorten your learning curve for Visual FoxPro 5.0! This document is also available for download at http://www.microsoft.com/vfoxpro/.
Appendix Added to Update Document
-
Micro Endeavors
Appendix. Microsoft has added the comprehensive Micro
Endeavors Appendix of FoxPro vs. Visual FoxPro language
changes to the Mastering Visual FoxPro CD Update Document.
Also available for download at http://www.microsoft.com/vfoxpro/
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