knex
A batteries-included SQL query & schema builder for Postgres, MySQL and SQLite3 and the Browser
Updated by @tgriesser
level
Fast & simple storage - a Node.js-style LevelDB wrapper (a convenience package bundling LevelUP & LevelDOWN)
Updated by @ralphtheninja
alasql
Use SQL to select and filter javascript data - including relational joins and search in nested objects (JSON). Export to and import from Excel and CSV
Updated by @mathiasrw
taffydb
TaffyDB is an opensouce library that brings database features into your JavaScript applications.
Updated by @biastoact