If we’ve been using an Entity Framework 4 model for some time, and we eventually want to switch the underlying database to a different vendor’s product (say, from SQL Server to MySQL), is it simple to adjust the table and column mappings in the entity model without needing to update any of the entity class code?
We’re trying to design code that is as database agnostic as possible, so I’d like to know in advance how much trouble we’re in for if we ever switch our databases around. Ideally, we’d like to not have to touch our applications that use our entity classes. I can’t seem to find any way in the entity designer or XML editor to adjust the underlying database column names without it giving me an error.
(I can, however, edit the entity’s property names in the designer while leaving the database column names alone, but that’s the opposite of what I need.)
Thanks!
EDMX is not database agnostic. SSDL part of EDMX is tightly coupled with database server (in case of MSSQL even with its version). You need separate SSDL for each supported database server.
I don’t understand how changing column names relates to database agnostic model. Reverse is true! If you need your database to have different column names for different server products you need separate mapping for each of them!
Changing column names when using model first is possible only if you modify T4 template used for generating database creation SQL script. But every time you create that script designer will delete whole your storage description (SSDL) and mapping (MSL) and replace them with a new one.
The easiest way to have database agnostic code is using code first but even then you can have problems with some type and feature inconsistency among servers.
If you want database agnostic ORM you should probably check NHibernate.