If Hydrate is about laying an object model over an existing database, why are there no tools to convert a relational schema into objects?
There are many commercial and open source tools that enable you to generate an object model from a relational schema. The problem with a schema generated in this way is that it shows its heredity. The data in a relational schema has generally been forced against its will into what, let’s face it, is a somewhat unnatural representation, in order to reap the benefits from the relational engine. Also, a typical relational schema that has been around for more than one system enhancement will often be less than ideal in structure. The decisions about how much to normalize, what primary and foreign keys are used, etc. is generally driven more by performance, resource needs and history, that by data modelling purity. Unless you are very lucky with your relational database schema, an object model generated from will always look like an object model generated from a relational schema. In summary, tools that write your object model from a database are impressive at first, because you make a lot
