SQLdown

A levelup backend with knex (sqlite3, postgres, and mysql tested and websql possible).

npm install --save sqldown

Also it doesn't come with any of the database backends so you need to install those yourself, one of

npm install --save sqlite3
npm install --save pg pg-query-stream
npm install --save mysql

In node locations should be connection strings (e.g. postgres://username:password@localhost/database), if it doesn't start with a 'dbType://' it is assumed to be the path for a local sqlite3 database. Table defaults to sqldown but can be overridden either by passing an table option or setting a query param (pg://localhost/database?table=tablename).

In the browser location will always be the table name.

Test setup and much else taken from level-js.

Setup

To get around the fact that postgres does not feature upserts instead of a simple table with 2 columns, key and value with key being the primary and unique key, instead we have a more complex setup with 3 columns id, key and value with id being an auto-incremented integer. When we get we query for the value with the given key which has the highest id.

This could lead to much excess data if you were to update the same key a bunch so it's set to periodically (by default every 25 puts) clean up any entries that aren't the max id for a given key.

Databases that support indexes on arbitrarily long fields have the key field index. If you know your keys or values are going to be shorter then a given length you may specify keyLength or valueLength option to limit it to that length, this is a prerequisite for mysql indexes.