Entity structure and dynamic schema

Question

I have inherited an application that speaks to many different customer databases.

Most of these tables in client databases have an identical design, but there are several tables with additional custom columns that contain tax information (I am a bad idea - I know ... I have not installed it).

These additional columns can be called anything. They are known at runtime because they can be found in another table.

I can configure EF to read / write these tables (skip dynamic columns), but I really need this information - since this is tax data.

I think my best route is to have a fixed model with added added properties that can be filled with these dynamic columns.

How can I get the Entity Framework to dynamically read and write these columns without using custom SQL statements with every call?

I can do extra reads and writes to read and write these extra columns separately (using custom sql) ... but there must be some way to override EF so that it knows about these extra columns and can handle them correctly.

Any help would be appreciated.

Answer 1

In the first step, you can directly query _INFORMATION_SCHEMA_ or other metadata tables to find out if the tables in which you want your context to be included have these columns. Based on this information, you can use a different DbContext (perhaps a common movie), but create it using the MappingConfiguration , in which you either ignore the columns if they are not there, or map them to the POCO class that your context desires.