Similar features of LINQ

Question

Is there any feature similar to LINQ (.NET) in different languages like JAVA, PHP, etc?

Answer 1

There are many languages that have syntax or library functions for operating on sequences of objects in a mostly functional way. For example Python has lambda functions, list comprehensions, generators, and the itertools module.

However I don't know of any language that can get anywhere near everything that LINQ can do as cleanly and concisely. Remember that LINQ is not just a way to operate on in-memory structures - LINQ has many providers that share a similar interface:

• LINQ to Objects
• LINQ to XML
• LINQ to SQL
• etc..

Microsoft have done a good job with LINQ. I am sure some other languages will take inspiration from the success of LINQ and consider how to add similar features in the near future.

Answer 2

While basic LINQ features, like Select (map) and Where (filter) are present in almost all contemporary programming languages, constructing SQL "on the fly" and lazily is a work for ORM

For example, Django ORM allow you to use such syntax for making a query:

Posts.objects.filter(user=peter).annotate(comment_count=Count('comment')).order_by('comment_count')

It's something like (not very sure) in LINQ:

from p in posts
where p.user == peter
select new { post = p, comment_count = comments.Where(c => c.post == p).Count() }
order by comment_count

Answer 3

Sure there are, but php is a programming language and not a framework like .net framework. So if you want to use features, you should download some libraries, orms or frameworks to get higher effectivity. I dont think that php has that powerful feature, that could be an equivalent of linq.

Answer 4

Scala has for-comprehensions that provide similar functionality as the LINQ.

Example: Find all attendees with name Fred that speak Danish.

C#:

var xs = 
  from att in attendees
  where att.name == "Fred"
  from lang in att.spokenLanguages
  where lang == "Danish"
  select att;

Scala:

val xs = for {
  att <- attendees
  if att.name == "Fred"
  lang <- att.spokenLanguages
  if lang == "Danish"
} yield att

Answer 5

http://code.google.com/p/phpreboot/ implements LINQ partially in a PHP-like language.