The LINQ project is the ".NET Language Integrated Query"
from the "The LINQ Project" , Don Box September 2005:
".NET Language Integrated Query defines a set of general-purpose standard query operators that allow traversal, filter, and projection operations to be expressed in a direct yet declarative way in any .NET-based programming language. The standard query operators allow queries to be applied to any
IEnumerable<T>-based information source. LINQ allows third parties to augment the set of standard query operators with new domain-specific operators that are appropriate for the target domain or technology. More importantly, third parties are also free to replace the standard query operators with their own implementations that provide additional services such as remote evaluation, query translation, optimization, etc. By adhering to the conventions of the LINQ pattern, such implementations enjoy the same language integration and tool support as the standard query operators."
This is a short explaination of LINQ. JLINQ (Java Edition) does not exist ( as far as I know ), but Hibernate does. Hibernate is :
"Hibernate is a powerful, high performance object/relational persistence and query service. Hibernate lets you develop persistent classes following object-oriented idiom – including association, inheritance, polymorphism, composition, and collections. Hibernate allows you to express queries in its own portable SQL extension (HQL), as well as in native SQL, or with an object-oriented Criteria and Example API."
Hibernate is even embeded in Oracle 10g ( I think that even in the express edition ). The point is, just like JUnit was latter adopted by the .NET community using the NUnit , there exist a NHibernate edition for .NET , which even has a Quick Start Guide.
In a related subject I ran into a 101 LINQ Samples, which I hope is not out dated.
I you want to learn more about NHibernate here's a NHibernate Tutorials link.