Media Share 9/MEDIASHARE_09.ISO/private/mpc93mar.zip/APPROACH.DAT

Text File | 1993-02-14 | 12KB | 236 lines

                      Approach Links Diverse Databases

     By: Steven Friedman

     The task of database creation and management has always been a
     labyrinth best left to the MIS overseers and programmers. Windows has
     not changed this. There are few completely Windows-based,
     fully-relational database programs, although more are scheduled for
     release in the later part of 1992.

     What we do have is a growing roster of hybrid programs that serve as
     front ends for existing databases. Generally, these programs use
     object-oriented concepts to create a Windows portal for one or more
     existing database formats, incorporating DDE, fonts, graphics, and
     multi-tasking. They allow users to create database front ends with
     little or no programming. While they are not true relational database
     programs in the purest sense, they provide 80% of the functional needs
     of most database users.

     Most existing database programs are built on procedural commands that
     store and manipulate data. The basic database engine controls the
     structure of the database such as field types, lengths, names, and the
     pointers that find the stored records. Procedural code sits on top of
     this engine to allow the user to create forms, reports, and turnkey
     applications.

     The new hybrids do not attempt to replicate these engines, but simply
     attach onto them and allow the user to treat that data and its
     corresponding properties as objects. Thanks to the Windows GUI,
     additional properties such as fonts, colors, and even graphics can be
     attached to these objects.

     In these hybrid programs, the distinction between reports and forms is
     less distinct. You could not imagine being able to edit data on a
     dBASE report. Yet one of the hybrids, Approach, lets you edit data on
     reports, and display summary data on forms. Each record can be edited
     or formatted in a variety of ways because all records are treated as
     objects, not as lines of procedural code.

     Another aspect of the hybrid programs is their ability to work with
     relational features of databases. Unlike flat-file databases, which
     store all data in a single type of record, relational databases use
     multiple data tables or files to store specific types of information,
     then link it through a common column. Most of the powerful databases
     in use today are relational, since this type of database provides a
     more efficient method of dealing with one-to-one, one-to-many, and
     many-to-many relationships.

     An example of a one-to-many relationship would be a client placing
     several orders. If the customer has multiple orders in a flat-file
     database, you would have to repeat the customer information each time,
     as well as the product information, pricing, etc.

     Hybrids also have the unique ability to link information from
     different database engines and to create relationships between them.
     While traditional databases store specific types of information in
     separate tables, they generally cannot cope with tables in different
     database formats.

     Imagine, for example, that your customer data (name, address, phone
     number, etc.) is stored in dBASE or Paradox, but transactions (e.g.,
     orders) are stored in Oracle. Until now there has been no easy way to
     link them without elaborate and complex conversion processes. With
     Approach, the problem is eliminated, since you are treating each
     record as an object, and are not tied to the procedural code that is
     behind it. In this manner, dBASE, Paradox, and Oracle data can all
     coexist in harmony on the same form and reports, without complicated
     procedures to convert them.

                                  Approach

     Approach uses the concept of creating views that link together
     reports, forms, and database records. These files may be dBASE,
     Paradox, SQL, or Oracle files. The view presents the information and
     allows you to organize it into forms and reports. Unlike traditional
     forms and reports in their DOS counterparts, the data is editable in
     both.

     You may also link or embed pictures onto the form design or into a
     picture field of the database. In this fashion, you can store text and
     graphical data together in the same form. Using DDE, Approach can
     actually alter graphical data (such as an Excel chart) as you enter
     it.

                                  Forms

     Approach handles data through forms, reports, and mailing labels. When
     you open or create a database, it instantly sets up a basic form in
     the design mode, using the fields you select. You may use this as-is,
     or alter it and embellish it with graphics, shading, color, and text.
     To view the data you switch to the Browse mode and toggle VCR-style
     arrow buttons on the top of the screen to move through the records.

     I liked the way Approach lets you set up global preferences to
     pre-define the size, typeface, and color of data entry text, the
     position of field labels in relation to the entered text, etc. You may
     also change these individually by double-clicking anywhere on a field.
     When you do, all the options are presented, including the field
     definitions, so you can alter the database structure on the fly. To
     change a field size, you simply grab a handle and move it in or out.
     To move a field, click on it once, then move it to where you want. You
     have several options for formatting how data is presented. You may
     have the user enter a value, select from a list, or use a combination
     of both. The list restricts you to the choices on the list.

     The text-plus-value list allows you to enter a value not on the list
     into the field. To create a value list, you must pre-define the
     options. I was disappointed that it would not allow you to assign the
     column or database field name to the value list, so that all
     previously entered values would come up in a popup list. I was told
     this is slated for a future release. You can also have it default to
     the current date, time, an auto-numbered value (starting from an
     assigned value and incrementing by an assigned value), or the most
     recently entered value. Approach has a limited ability to validate
     entries. Properties that can be checked are: filled in, true or false,
     unique, within a range, in a specific list of values, or existing in a
     database.

                                Joining Databases

     To create a relationship between two database files, you open one or
     more databases, then highlight the linking columns in each. This
     creates a join between the two, and both fields can then be used. You
     may continue to do this with multiple databases and tables to create a
     series of very complex relationships. Since you often want to display
     multiple transactions on a single form, you may create a repeating
     panel. This displays a scrolling region of multiple rows of data on
     the many side of the one-to-many relationship. Each row is linked by a
     matching column. In this case, the matching column does not even have
     to be from the same database program or have the same name.

                                Powerful Macros

     In place of a procedural language, Approach uses macros that automate
     some command steps. After you create the macro, you may then assign it
     to a button on the form. When the user presses the button, the macro
     (or a series of macros) is executed. While this is a powerful feature,
     it does not take the place of a procedural language. Moreover, unlike
     the other features in Approach, the macro language is inadequately
     documented. Not enough examples are given in the tutorial to
     familiarize the user with all the options. I found myself caught in
     several loops that kept repeating the same macro, with no way to break
     out of it short of the "three-finger salute." Another frustrating
     aspect of the macros is their inability to use global variables. A
     global variable is just a temporary vessel that stores information
     that is either entered from the keyboard, looked up from a select
     statement, or calculated. This saves having to use up record space to
     hold values that are needed for only a short time. It is also
     confusing how to get from one form or report to another and back
     again. From the examples in the templates, it appears that the feature
     has some powerful capabilities, but I was unable to reverse-engineer
     them well enough to gain a good understanding of them.

                                  Summary

     Approach is one of the first hybrid programs that does not require
     extensive programming skills to get up and running. It is
     user-friendly and makes excellent use of top-bar icons and dialog
     boxes for creating forms, reports, and fields. Within four hours, I
     was able to get a form and report running. A few things that are
     lacking or inadequately documented prevent this program's first
     release from being a 10.

     The weak points include:

     * Lack of context-sensitive help<197>or, in many cases, any help. The
       lack of help for macros suggests that they were added on as an
       afterthought.

     * Not enough functions. Even though Approach contains numerous
       functions, they don't seem adequate for all the ways that data needs
       to be manipulated.

     * No way to perform lookups on values existing in the same table, and
       no way to modify a link to a table based on a specific criterion such
       as month or year.

     * Inability to use a table as the basis of a selection list. Instead,
       all of the literal values must be typed in.

     * Password security is only for the entire view. You cannot assign a
       user hierarchy, or limit forms (or fields on forms) based on
       passwords.

     * Lack of style sheets for globally defining text fonts, colors,
      lines, etc. While being able to define the global defaults is a step
      in the right direction, it would be better to have a selection of
      style sheets for this purpose.

     Approach's strong features include:

     * Easy to connect multiple database files from different database
       programs into a single view, and utilize that data in reports and
       forms.

     * Easy to assign multiple attributes to a selection of objects at
       once.

     * Easy to create forms.

     * Able to use OLE to link pictures to objects and can actually
       incorporate pictures into records.

     * Automatically creates fields for a form.

     * Automatically formats a report, and allows you to select from
       standard, columnar, or summary formats.

     * Easy to make joins among many different databases and tables.

     * Easy to create scrolling regions of linked data.

     * Well designed tutorial, but overall documentation seems fuzzy in
       places, especially with object linking to pictures, and macros.

     * Easy to create mailing labels.

     * Able to view zoomed or contracted images of reports and forms.

     * Ability to change the tab order.

     * Ability to globally define attributes such as pen color, fonts, etc.

     * Ability to group objects.

     * Extensive formatting tools: grids, rulers, alignment tools, and
       zooming.

     * Excellent use of top icon bar for functions, and a well-designed
       user interface.

                     Approach [$199 list; $99 to SPCUG members]
                     Approach Software 311 Penobscot Dr.
                     Redwood City, CA 94063