HTML5 localStorage & SQL

问题:

I understand that HTML5 "localStorage" is a key:value store but I am wondering if there is a Javascript library available that offers a more SQL-ish API?

回答1:

Check out Will HTML5 be SQL-free? and DOM Storage: a Cure for the Common Cookie for some links and opinions.

回答2:

W3C Database specification says:

User agents must implement the SQL dialect supported by Sqlite 3.6.19.

As of now, at least Google Chrome supports SQL dialect. I have checked myself.

回答3:

You should use HTML5 database storage (it supports SQL through transactions). a tutorial here: http://www.html5rocks.com/tutorials/webdatabase/todo/

回答4:

HTML5 local database storage comes with a SQL interface by default, if I'm not mistaken

Here is a Webkit post with some examples: http://webkit.org/blog/126/webkit-does-html5-client-side-database-storage/

Currently, Chrome forces you to use Gears, which is slightly different, but still SQL-based. Future versions of Chrome will follow the HTML5 spec, however.

回答5:

Try this: http://kailashnadh.name/code/localstoragedb/

回答6:

You can try Alasql. It supports standard SQL language and keeps data in memory or localStorage. There are sevelar ways, how to use Alasql with localStorage. Below you can see how to create localStorage database with name "Atlas", attach it to Alasql as "MyAtlas", then you can work with tables like any other database. By default, Alasql uses AUTOCOMMIT ON mode, so it saves data to localStorage after each SQL statement.

This is a sample:

alasql('CREATE localStorage DATABASE IF NOT EXISTS Atlas');
alasql('ATTACH localStorage DATABASE Atlas AS MyAtlas');
alasql('CREATE TABLE IF NOT EXISTS MyAtlas.City (city string, population number)');
alasql('SELECT * INTO MyAtlas.City FROM ?',[[{city:'Vienna', population:1731000}, 
    {city:'Budapest', population:1728000}]]);
var res = alasql('SELECT * FROM MyAtlas.City');

Play with this sample in jsFiddle. Run this sample two or three times (or reload page), and you will see, how the number of lines will grow in the table.