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seneca-postgres-store

Seneca data store plugin for PostgreSQL

A Seneca.js data storage plugin

seneca-postgres-store

seneca-postgres-store is a PostgreSQL database plugin for the Seneca MVP toolkit. The plugin is using the node-postgres driver. For query generation it uses internally the seneca-standard-query plugin and the standard functionality can be extended by using the seneca-store-query plugin.

Usage:

var Seneca = require('seneca');
var store = require('seneca-postgres-store');

var DBConfig = {
  name: 'senecatest',
  host: 'localhost',
  username: 'senecatest',
  password: 'senecatest',
  port: 5432
}
...

var si = Seneca(DBConfig)
si.use(require('seneca-postgres-store'), DBConfig)
si.ready(function() {
  var product = si.make('product')
  ...
})
...

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$(function (errentity) { ... })
entity.load$({id: ...}, function (errentity) { ... })
entity.list$({property: ...}, function (errentity) { ... })
entity.remove$({id: ...}, function (errentity) { ... })

Supports Seneca versions from 0.6.5 up to 1.4.0

The standard Seneca query format is supported. See the seneca-standard-query plugin for more details.

By using the seneca-store-query plugin its query capabilities can be extended. See the plugin page for more details.

In seneca-postgres-store 2.0 the internal CamelCase to snake_case column names conversion was removed.

To update from seneca-postgres-store 1.x to 2.x on systems built with seneca-postgres-store 1.x you must provide to the plugin through its options the functions that do the CamelCase to snake_case conversion and back. Any other name transformations to and from database column name can be also made with these. Example:

var DefaultConfig = {
...
  fromColumnNamefunction (attr) {
    // apply some conversion on column names 
    return attr.toUpperCase()
  },
  toColumnNamefunction (attr) {
    // convert back column names 
    return attr.toLowerCase()
  }
}
seneca.use(require('seneca-postgres-store'), DefaultConfig)

For a fully functional CamelCase to snake_case implementation sample please look in the postgres.test.js at the 'Column Names conversions' test code.

By default queries are limited to 20 values. This can be bypassed by passing the nolimit option, which if set to true will not limit any queries.

To filter the fields returned from the list operation, pass a fields$ array of column names to return. If no fields$ are passed, all fields are returned (i.e. select * is used). e.g.

query.fields$ = ['id', 'name']

Note: The implicit id that is generated on save$ has uuid value. To override this you must provide entity.id$ with a desired value.

To generate custom IDs it is exposed a seneca action pattern hook that can be overwritten:

seneca.add({role: 'sql', hook: 'generate_id', target: <store name>}, function (argsdone) {
  return done(null, {id: idPrefix + Uuid()})
})
 

As with all seneca stores, you can access the native driver, in this case, the pg connection object using entity.native$(function (err, connectionPool, release) {...}). Please make sure that you release the connection after using it.

entity.native$( function (err, client, releaseConnection){
  // ... you can use client
  // ... then release connection
  releaseConnection()
} )

To run the tests you need to have the docker image built and running, that is made executing npm run build then npm run start In another console execute npm test

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.