A Seneca.js data storage plugin
This module is a plugin for Seneca.js. It provides a storage engine that uses MongoDb to persist data and is ready for production use. It may also be used as an example on how to implement a storage plugin for Seneca.
For a gentle introduction to Seneca itself, see the senecajs.org site.
To install, simply use npm. Remember you will need to install Seneca.js separately.
npm install seneca
npm install seneca-mongo-store
To run tests, simply use npm:
npm run test
var seneca = require('seneca')()
seneca.use('mongo-store', {
name: 'dbname',
host: '127.0.0.1',
port: 27017
})
seneca.ready(function(){
var apple = seneca.make$('fruit')
apple.name = 'Pink Lady'
apple.price = 0.99
apple.save$(function (err,apple) {
console.log( "apple.id = "+apple.id )
})
})
You don't use this module directly. It provides an underlying data storage engine for the Seneca entity API:
var entity = seneca.make$('typename')
entity.someproperty = "something"
entity.anotherproperty = 100
entity.save$(function (err, entity) { ... })
entity.load$({id: ...}, function (err, entity) { ... })
entity.list$({property: ...}, function (err, entity) { ... })
entity.remove$({id: ...}, function (err, entity) { ... })
The standard Seneca query format is supported:
-
.list$({f1:v1, f2:v2, ...})
implies pseudo-queryf1==v1 AND f2==v2, ...
. -
.list$({f1:v1,...}, {sort$:{field1:1}})
means sort by f1, ascending. -
.list$({f1:v1,...}, {sort$:{field1:-1}})
means sort by f1, descending. -
.list$({f1:v1,...}, {limit$:10})
means only return 10 results. -
.list$({f1:v1,...}, {skip$:5})
means skip the first 5. -
.list$({f1:v1,...}, {fields$:['fd1','f2']})
means only return the listed fields.
Note: you can use sort$
, limit$
, skip$
and fields$
together.
As with all seneca stores, you can access the native driver, in this case, the node-mongodb-native
collection
object using entity.native$(function (err,collection) {...})
. Below we have included
a demonstration on how to write a SQL query using Mongo aggregate in Seneca:
SELECT cust_id, count(*) FROM orders GROUP BY cust_id HAVING count(*) > 1
var aggregateQuery = [
{
$group: { _id: "$cust_id", count: { $sum: 1 } }
},
{
$match: { count: { $gt: 1 } }
}
];
orders_ent.native$(function (err, db) {
var collection = db.collection('orders');
collection.aggregate(aggregateQuery, function (err, list) {
if (err) return done(err);
console.log("Found records:", list);
});
});
You can also use: entity.list$({f1:v1,...}, {native$:[{-mongo-query-}, {-mongo-options-}]})
which
allows you to specify a native mongo query per node-mongodb-native
We encourage participation. If you feel you can help in any way, be it with examples, extra testing, or new features please get in touch.
Copyright Richard Rodger 2015, Licensed under MIT.