Create SQL queries programatically in Node.js. Loosely based on Rails' ActiveRelation. Works with node postgres.
Install the module with: npm install db-query
You'll also need to npm install pg
.
You'll need a config/database.yml that looks something like :
defaults: &defaults
host: localhost
development:
<<: *defaults
database: writebox_development
username: cheese
password: edam
production:
<<: *defaults
database: writebox_production
username: cheese
password: camembert
And optionally a config/queries.yml that looks something like :
(Note the optional use of parameters - $1, $2 etc)
news-search:
SELECT ts_headline(title, q, 'HighlightAll=TRUE') AS title, link, image, ts_headline(intro, q, 'HighlightAll=TRUE') AS intro
FROM (SELECT title, link, image, intro, ts_rank_cd(tsv, q) AS rank, q FROM news, to_tsquery($1) as q
WHERE tsv @@ q ORDER BY rank DESC OFFSET $2 LIMIT 20) AS results
news-search-count:
SELECT count(*) FROM news WHERE tsv @@ to_tsquery($1)
news-latest:
SELECT * FROM news LIMIT 10
And then use it like this :
// Typical connection pool
var db = require('db-query')(process.env.NODE_ENV);
// Optional separate connection pool
var dbProd = require('db-query')('production');
// Example callback
function someCallback(rows) {
console.log('Rows : ' + rows.length);
}
// You can use callbacks and/or events
// Programmatic query - so call .execute() as the last step
db.query('news', someCallback)
.select('*')
.on('error', function(err) { console.log(err); })
.on('end', function(result) { console.log(result[0]); })
.execute();
// Named query (from your config/queries.yml file) - no need to call .execute()
// name, query parameters, optional callback
db.named('news-search', ['syria', 20], someCallback)
.on('error', function(err) { console.log(err); })
.on('end', function(result) { console.log(result[0]); });
// Other example stuff
var options = { id: [1,2,3,4] };
// or options = { id: '1,2,3,4' };
db2.query()
.select('*')
.from('users')
.join('JOIN posts ON posts.user_id = users.id')
.order('posts.updated_at DESC')
.limit(10);
// Add some sample optional processing to the query
var food = 'cheese';
if (food) {
// Get people by food
q.join('JOIN foods ON foods.id = users.food_id')
q.param(food);
q.where('foods.name = ' + q.paramNo()); // This becomes : foods.name = $1
} else {
// Get people by id(s)
// q.ids is another form of q.param, but will join arrays and wraps the result in '{ }' braces.
q.ids([1,2,3,4]); // q.ids('1,2,3,4'); as an alternative
// This is using Postgres' ANY format rather than id IN blah because it's much more efficient
q.where('id = ANY(' + q.paramNo() + '::int[])');
// This becomes : id = ANY($1::int[])
}
// Prepare some event handlers and execute the query
q.on('row', function(row) { console.log(row); })
.on('error', function(err) { console.log(err); })
.on('end', function(data) { console.log(data); })
.execute();
In lieu of a formal styleguide, take care to maintain the existing coding style. Add unit tests for any new or changed functionality. Lint and test your code using Grunt.
v0.1.0
Copyright (c) 2013 Mark Selby
Licensed under the MIT license.