Is it good to introduce nHibernate for a legacy database in an ongoing project?

Question

I am working on a current ongoing project where, there are two instances of the database having different schemas for some of the tables and is being used for transfer from one to another.

Database schema is not well defined like,

• No Primary key for some of the tables
• Primary key as a composite key
• Foreign keys in composite primary keys
• Foreign key constraint referencing the primary key column of the same table
• Composite primary key has been referenced as a foreign key in another table
• Having more than 400 tables and will be increased

Application having very less OOPS concept implemented or let's say less objects used at all.

So, looking for some answers if at all, we introduce NHibernate with Repository pattern at this particular time, to faster the development process.

Cheers.

Answer 1

I have successfully introduced it into a project that had tons of custom sql and it worked quite successfully, hardest part was mapping the tables to an object model that was at least partly oksih. But other than that, it was good and it made things go a lot faster and helped with testing and got rid of a lot of SQL query issues.