arrays - Analog to SQL 'JOIN' for Javascript objects?

Question

What's a pragmatic analog to SQL 'JOIN' for tables represented as arrays of Javascript objects? Javascript Array.join and D3.js 'd3.merge` are not the same concept.

E.g. SELECT * FROM authors LEFT JOIN books ON authors.id = books.author_id?

First table:

var authors = 
[  { id: 1, name: 'adam'},
   { id: 2, name: 'bob'},
   { id: 3, name: 'charlie'}, ...
]

Second table:

var books = 
[  { author_id: 1, title: 'Coloring for beginners'}, 
   { author_id: 1, title: 'Advanced coloring'}, 
   { author_id: 2, title: '50 Hikes in New England'},
   { author_id: 2, title: '50 Hikes in Illinois'},
   { author_id: 3, title: 'String Theory for Dummies'}, ...
]

The tables are loaded from CSV using D3.js d3.csv(), so have D3.js already, open to other libs but generally prefer coding directly if not too far out of the way.

I see Native way to merge objects in Javascript which uses RethinkDB, which seems over the top for this, but this is the idea.

Answer 1

Basically, like this:

// first, build an easier lookup of author data:
var authormap = {};
authors.forEach(function(author) {authormap[author.id] = author;});

// now do the "join":
books.forEach(function(book) {
    book.author = authormap[book.author_id];
});

// now you can access:
alert(books[0].author.name);