The Lost Secrets Of Lookup()...

by Michael Meer

(Ed. Note: This article first appeared in The Pinter

FoxPro Letter. It is reprinted here with permission from

both the author and Les Pinter, publisher of The Pinter

FoxPro Letter.]

Would you like to replace 25 lines of code that execute in

.066 seconds with one command that executes in .002

seconds? Would you like to eliminate the need to set

relations between your main tables and the lookup tables

in your screens just to display some field from the lookup

table? Or maybe eliminate the need to tie those lookup

tables into your queries, thus speeding them up for

reports?

Good, now I have your attention, Lookup() is a powerful

command that is highly underrated. The Foxpro 2.6 on-

line help describes Lookup() as a function that “searches

a table/.dbf for the first record with a field matching the

specified expression.’ This simple explanation doesn’t

begin to give you the power of LookupQ. To understand

what Lookup() is actually doing, we will explore a UDF

that has the same functionality.

First, the UDF must accept the same four parameters

that LookupO accepts. These parameters are the return

field’s name, the search key, the locate field name and

the tag name.

PARAMETERS pcRetFld, pcKey, pcSeekFld, pcTagName

In the next section of the UDF, we must declare some

private variables and save the current work area.

PRIVATE jcCurrentAllas,;

JcCurrentOrder,;

JcType,;

jReturn Value

jcCurrentAlias ALIAS()

(Con't, page 7)

February 19, 1996, 7:30 PM - David Ingersoll, Select

Software Tools. David will be presenting Select OMT

Professional, a modeling tool for classes and use

classes, and its companion product, The Document

Generator.

March 18, 1996, 7:30 PM - Sally Wong, Computer

Resources Technology. Sally will be presenting a

system modeling toOl, FoxCase (distributed exclusively

in the US by Neon Software), that enables developers to

design and work through their system model, review their

assumptions, identify redundant fields and relationships,

produce a logic diagram (among others), etc., and then

output to the VFP DBC. She’ll also be bringing a copy of

the software to raffle off. (Only paid-up members will be

eligible for the drawing.)

April 15, 1996, 7:30 PM - Jonathon Melvin and Roger

Woodsmall. Jon will be talking about and demonstrating

using VFP to develop aps, frameworks, and class librar-

ies. Roger will be returning with his latest version of

AutoManual. To jog everyone’s memory, Roger demon-

strated his DOS product to LA Fox about 1-1/2 years ago

and everyone asked him about a Windows version.

(What this product does is automatically generate end-

user documentation for any FoxPro application to a MS

Word file.) He immediately started working on a Win-

dows product and just about the time it was close to

(Con't, page 2)

The LA Fox Developer

A Newsletter for FoxPro Application Developers in Southern California

February 1996

Out and About

by Barry R. Lee

The February meeting of LA Fox will be held

on Feb.19, 1996, at 7:30 PM at our regular

meeting place (the Torrance Airport, 3301

Airport Drive, in Torrance). For details on

how to get there, see the map on the back

page.

In this issue

Developing EXE’s in VFP

Page 3

Polymorphism Explained

Page 4

Simple Stuff

Page 6

VFP SCATTER NAME Command

Page 9

and more!