Thank you for the answer Craig. I think I have not expressed myself clearly. I don't want to overstate the frequency with which attributes will need to be stored as records in Object-Atribute-Value tables (or is it Entity-Attribute-Value) rather than as columns in the application we are developing.

Most of the attributes of our BOs will be known at development time, but we have found that an infinity of new types of time and income categories (that follow different business and tax rules) appear as time goes by and we don't want to create new columns in several tables every time this happens. Rather, we would like to store time and income values as records in a detail table rather than columns in a transaction table, yet have them show up as attributes on a transaction BO. That is what I mean by storing some attribute values as records rather than columns in a table.

We would like this to be handled by the framework we choose. I anticipate there would be an attribute definition table with defaults that is referred to when adding properties to BO.

What do you think?

Alex





>If you're going to store business attributes, you may be better off with a NoSql solution such as MongoDb.
>
>If you want tools to help automate database evolution, go with SqlServer and use Entity Framework along with EF Code Migrations. Small customer sites can probably get by with SQLServer Express.
>
>If you want a no-cost SQL solution, look into Postgress rather MySQL, but you'll give up the automation of Code Migrations.
>
>Use a good CSS Framework, such as Bootstrap. Don't roll your own CSS.
>
>>A short while ago I wrote about our wish to migrate a successful vfp app to a language with a more abundant developer supply long term.
>>
>>As a cautious first step, we think it would be good to start with a smaller new and related app in order to gain experience. So this thread is about that new app. A big goal is to choose tools that give developer productivity and avoid the need to write repetitive code.
>>
>>So far we are leaning in the following ways but are open to suggestions:
>>1) Web based
>>2) .NET
>>3) Undecided between SQL Server and MySql for reasons of cost to customer vs advantages to developer (what are the advantages to developer?)
>>4) Use MVC framework
>>4) Use tools that automate database evolution at user site
>>5) Use tools that simplify business rule evolution with valid date range for the rules
>>6) We would *really* like it if the tools we chose allow us to store some BusinessObject attributes in Object-Attribute-Value form rather than exclusively as columns in a table
>>
>>All comments are welcome.
>>
>>Alex