Object Relational Mapping tools like Hibernate have helped developers make huge productivity gains in dealing with relational databases in the past several years. ORMs free developers to focus on application logic and avoid writing a lot of boilerplate SQL for simple tasks like inserts or queries.
However, the well-documented problems with object-relational impedance mismatchinevitably cause headaches for developers. Relational databases are a specialized technology built on sound concepts, but they don’t necessarily line up to the object-oriented world. There are a few approaches and styles to using ORMs which have various pros and cons.
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