INTRODUCTION   TO    FOCUS

The objective of  "Focus for beginners" section is to help new Focus users to get an elementary idea of  Focus and start using their Focus applications. It is as such not a comprehensive and exhaustive compilation of Focus concepts and techniques. Since I have access to only  Mainframe Focus, Rel 6.8  I am unable to incorporate features that are unique to some platforms.
I first started working on this when I trained my Project mates for our  Y2K
conversion project . As our Focus applications were only batch , I have not worked on  online Focus . So whatever I have mentioned on online Focus is what I have understood after reading the IBI's Focus manual .
All the material presented here is what I have either directly quoted from the IBI's Manual or
my interpretation of it. I referred only to  IBI's manual for learning Focus.
 WHAT IS FOCUS
   4 GL  VS   3 GL
    BENEFITS OF  FOCUS (& OTHER 4GL’s)
     FEATURES OF  FOCUS
     WHO  USES FOCUS
SUMMARY
 
 FOCUS  INTRO
  FOCUS is a 4 GL  or  a  non-procedural language . It means that the end user who has no formal   technical skills can still use the language to  retrieve  information from databases for  processing and reporting needs.
4 GL  VS   3 GL
A   classic 3 GL is cobol. Here the programmer has to have an idea of the field lay out, record   structure , etc. for him to process the information which  is read  from an external file or  an Database.  He has  to  have an understanding of how data is handled and processed by the computer  for him to efficiently use the features available for reporting purposes ( or for any other use ). However this level of technical  skills cannot be expected by everyone. Also there is a need for a large number of ad-hoc reporting . This if coded in  Cobol, will result in a large development time. A 4 GL solves this by  reducing the development time, this is because  a 4 GL consists of  English  like statements  and  anyone with a  basic understanding of the 4 GL can  start using the facilities offered by a 4 GL.
BENEFITS OF  FOCUS (& OTHER 4GL’s)
  1.   Increased  productivity  of programmers as application development time is reduced.
  2.   Non programmers  (end users ) can  start using it with minimal technical skills.
  3.   Freedom from Data Definition. The  end user need not be concerned with how  each field is defined.
 
FEATURES OF  FOCUS
 
  1.  Availability  across platforms. Focus is available across a large number of both H/W and S/W platforms. It can be run  on VMS,   UNIX,  DOS,   OS/2 ,   LAN and  a  number  of   operating systems  on  M/F’s .
  2. Focus is consistent across  these platforms  i.e.,  the language syntax changes very little.
  3. Independence  from data source.
  4. FOCUS  can use data from many sources. Flat files created by COBOL,  IDMS data   bases, ORACLE etc..
  5. Focus has its own data base,  and  can work on FOCUS files just as it can on external  files.
  6. Security Features.  DBA level security features include READ access, write only access,  access to only specific  field (s)  and also to specific field value(s) etc.
WHO  USES FOCUS
        FOCUS is designed to be used by both end users and  application developers.   The end users generally tend to use it for Reporting purposes and to run applications created by the application developers.
SUMMARY
                             FOCUS  is  a  complete information control system with comprehensive features for   entering , retrieving, maintain and  analyzing data.  It  is designed to be used by both users with no formal training  in data processing and also by  Data Processing Pros. The non-procedural Focus language is  designed to  replace traditional  programming languages.  The simplicity of the command syntax ensures this.

                                CLICK HERE  for  introduction to the FOCUS environment.