Question

Currently I’m adjusting a system that works with Entity Framework to connect to a SQL Server 2008 R2 database.

For the new part the key users need to add, change and remove entities that the normal users can use. Before I make a system that saves objects with names and with attributes I wanted to look if it is possible to create the database dynamically with the entities that the key users are giving (through a simplified entity designer).

I’ve search a little bit but on the internet but didn’t find something quite like this. Maybe someone here knows something to push me in the right direction?

Answer 1

It sounds like you are best off by really defining tables, columns, indexes and foreign keys dynamically. If you were to use a “database of databases” schema with entities and attributes you would be unable to effectively index the database. Queries become extraordinarily slow and nasty.

You can query and change the database schema using SQL Server Management Objects (SMO). I have used them multiple times. They work and are quite nice to work with.

I’m not convinced that Entity Framework brings much to the table here. EF is good for expressing queries and DML on a static schema. If you were to use a dynamic schema you lose most of the benefits. Of course, some benefits remain such as entity key management and being able to use Entity SQL instead of T-SQL. On the downside you have to create all EF metadata at runtime (probably generate EDMX files or dynamic assemblies).

I think it is not worth it. I’d strongly consider building a database schema at runtime and executing queries against it using dynamically built T-SQL. It is much easier to do this than work against the system with EF.

In that sense you are back to DataTables and GridViews which was considered good style even 5 years ago. It’s probably not too bad.