Hence, if the original system is not documented, then I would strongly suggest that a ER diagram of the tables be created. Not only does this aid in the conversion process, it allows one to "see" the big picture. This "picture" will save a large amount of time in both the conversion process, and design of the new system. When my ER diagram was done, I pasted it on wall in view at all times. It was worth it heaps of gold.  Appendix #1 has an actual example of mine.


So, given the above, I will make my first trap warning about converting software from Pick to Ms-Access/SQL


Conversion Got ya #1:

Pick allows you more freedom to make mistakes from a table design point of view. SQL does not. You need more effort and skill to get the SQL table design correct. So, make sure your data structures (tables) are of a good design.



Code and business rules:

It is interesting how I just ranted about how you must get the table design correct. In fact, I will just assume that a good job is going to be done in the table area. We are wasting time if we cannot assume the table design is good. Ok, so if the table design is good, then it not a problem anymore is it?

So, then .just what is the problem we are left to deal with ?

Where the conversion from Pick to VB/SQL will kill you is in the business rules.

I am going to say this again:

Conversion Got ya #2:

Where the conversion from Pick to VB/SQL will kill you is in the business rules.


While Pick may be really great from a data point of view, it shines when it comes to business rules. I'll define business rules in my context, since we hear the term all the time.

Business rules  =  code that manipulates the data

Far too many of the new "mainstream" database people seem to think that a application is a bunch of tables, and screens to enter data. Far from it. If this was the case then we would not need programmers anymore. We would only need people to build data entry screens and tables. This simple "table" approach is why Pick to SQL applications fail. In fact it is why a lot of conversion projects fail. One just has to read the disaster enclosed in appendix 4 to get an idea of how wrong things can go. To be fair, the disaster outlined in this appendix 4 is due to the people involved, however the ability of the Pick system must also be considered here.

[Image][Image]