What is JSINQ?

JSINQ is the JavaScript library that allows you to write SQL-like queries against arrays and DOM node lists.

JSINQ is a complete implementation of LINQ to Objects (the .NET 4.0 version) in JavaScript. What that means is that if you know LINQ and you know JavaScript, you know JSINQ. JSINQ is both an API-compatible implementation of System.Linq.Enumerable and a complete query-expression compiler. That's right: you can write LINQ-style queries in JavaScript. And if that isn't enough: JSINQ is also very liberally licensed, well-document, well-tested (the Enumerable-part) and a stable version has just been released. So give it a go!

What does it look like?

Let's say you have a list of customers and you want to assemble a list of your customers' lastnames, ordered by their frequency. With JSINQ, you can write something like this:

var result =
    customers.groupBy(function(customer) {
        return customer.lastname;
    }).
    select(function(g) {
        return {lastname: g.key, count: g.count()};
    }).
    orderByDescending(function(r) {
        return r.count;
    });

This will do the job, but it's also rather difficult to read. That's why JSINQ also lets you write the following:

var query = new jsinq.Query('\
    from customer in $0 \
    group customer by customer.lastname into g \
    select {lastname: g.key, count: g.count()} \
    into r \
    orderby r.count descending \
    select r \
');

query.setValue(0, customers);
var result = query.execute();

Confused? What's with all the backslashes? Please read: JSINQ in a nutshell.

What can I do with JSINQ?

• Write arbitrarily complex queries against JavaScript arrays, DOM node lists or your own enumerable types
• Find elements in the HTML DOM tree using SQL-like queries
• Dynamically create HTML elements from JSON you have received via XMLHttpRequest in a declarative manner
• Tinker with XML and turn it into something else
• Combine it in interesting ways with the JavaScript-/Ajax-frameworks you are already using
• Write less code by exploiting the power of declarative programming
• And for the ambitious: write raytracers, monadic parser combinators, etc.

Using JSINQ

• JSINQ in a nutshell(new to JSINQ?, read this!)
• JSINQ Documentation
• Frequently asked questions