nHydrate is an object-relational mapping (ORM) solution for the Microsoft .NET platform providing a framework for a relational database to be mapped to .NET objects. It is designed to alleviate the drudgery software developers experience writing persistence domains.
Object-relational mapping in computer science is a programming technique for converting data between incompatible type systems using object-oriented programming languages. This creates, in effect, a "virtual object database" that can be used from within the programming language. There are both free and commercial packages available that perform object-relational mapping, although some programmers opt to construct their own ORM tools.
.NET Framework is a software framework developed by Microsoft that runs primarily on Microsoft Windows. It includes a large class library named as Framework Class Library (FCL) and provides language interoperability across several programming languages. Programs written for .NET Framework execute in a software environment named the Common Language Runtime (CLR). The CLR is an application virtual machine that provides services such as security, memory management, and exception handling. As such, computer code written using .NET Framework is called "managed code". FCL and CLR together constitute the .NET Framework.
A relational database is a digital database based on the relational model of data, as proposed by E. F. Codd in 1970. A software system used to maintain relational databases is a relational database management system (RDBMS). Virtually all relational database systems use SQL for querying and maintaining the database.
The MIT License is a permissive free software license originating at the Massachusetts Institute of Technology (MIT). As a permissive license, it puts only very limited restriction on reuse and has, therefore, an excellent license compatibility. The MIT license permits reuse within proprietary software provided that all copies of the licensed software include a copy of the MIT License terms and the copyright notice. The MIT license is also compatible with many copyleft licenses, such as the GNU General Public License (GPL); MIT licensed software can be integrated into GPL software, but not the other way around.
nHydrate was originally created in 2003 as a private project to solve the issues with the .NET Framework 1.1. Using ADO.Net Datasets is cumbersome and error prone, so a small generated framework was created to relieve developers of the CRUD work. As a private project it was later inspired by the work of the NHibernate group.
NHibernate is an object-relational mapping (ORM) solution for the Microsoft .NET platform. It provides a framework for mapping an object-oriented domain model to a traditional relational database. Its purpose is to relieve the developer from a significant portion of relational data persistence-related programming tasks. NHibernate is free as open source software that is distributed under the GNU Lesser General Public License. NHibernate is a port of Hibernate.
nHydrate was a private project from 2003 until 2009. It was used at various companies in the Atlanta, Georgia, area but never widely released. It was publicly released on September 10, 2009.
nHydrate is built on the .NET Framework 4.0.
From version 5.0 and above, the entire framework has been reworked to use only Entity Framework as it internal data access layer. The modeler is now visual with a main diagram like other modeling products. All code interactions are simply Entity Framework now so there is no learning curve for developers when using the generated output.
Entity Framework (EF) is an open source object-relational mapping (ORM) framework for ADO.NET. It was a part of .NET Framework, but since Entity framework version 6 it is separated from .NET framework.
Feature summary
nHydrate's primary feature is mapping .NET objects to an SQL server database. The CRUD layer (create, update, delete) is also implemented. There are numerous retrieval mechanism facilities. nHydrate generates the SQL for all CRUD operations as well as advanced LINQ capabilities. The product is not database portable. The framework is designed to work exclusively with Microsoft SQL Server. There is an internal project to use MySql but this is not yet a public release.
SQL is a domain-specific language used in programming and designed for managing data held in a relational database management system (RDBMS), or for stream processing in a relational data stream management system (RDSMS). It is particularly useful in handling structured data where there are relations between different entities/variables of the data. SQL offers two main advantages over older read/write APIs like ISAM or VSAM. First, it introduced the concept of accessing many records with one single command; and second, it eliminates the need to specify how to reach a record, e.g. with or without an index.
Language Integrated Query is a Microsoft .NET Framework component that adds native data querying capabilities to .NET languages, originally released as a major part of .NET Framework 3.5 in 2007.
The tool is entirely sited within Visual Studio.NET and all model maintenance and generation is handled directly from the environment. There are no XML files or other complex configuration scenarios to navigate like almost all other ORM tools. The VS.NET plugin GUI editor provides an interface to interact with a visual model and edit a model.
History
nHydrate was started by Michael Knight, and later added Chris Davis. By 2006, the platform had much of its current functionality, minus LINQ, and was being used in applications in the Atlanta area. By 2009, the advanced functionality had been added like inheritance, LINQ, and VS.NET integration.
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