basic restify/node.js based server for providing GeoJSON features

geojson.js

// npm install restify pg

/**
 * Configure the tables and the columns required as properties
 */
var tables = {
    'boundary' : { geom:'polygon', cols:['id', 'area_id', 'org_id'] },
       'stage' : { geom:'route',   cols:['id', 'event_id', 'name', 'outandback', 'start_time', 'num', 'distance'] },
    'stagepoi' : { geom:'point',   cols:['id', 'stage_id', 'type' ] }
};

var connString = 'tcp://username:password@host:port/dbname';

////////////////////////////////////////

var restify = require('restify');
var pg = require("pg");

function byProp(req, res, next){

    var vals = []

    var clause = "WHERE " + req.params.prop + " = $1"
    vals.push(req.params.id)

    execute(req,res,next,clause,vals)
}

function execute(req, res, next, clause, vals) {

    var table = req.params.table;
    // check table exists
    var cfg = tables[table];
    var cols2props = cfg.cols.join(",")
    var geom = cfg.geom

  
    
 
    pg.connect(connString, function(err, client) {
 
        // from http://www.postgresonline.com/journal/archives/267-Creating-GeoJSON-Feature-Collections-with-JSON-and-PostGIS-functions.html
        var sql = "SELECT row_to_json(fc) " + 
                    "FROM ( SELECT 'FeatureCollection' As type, " + 
                    "row_to_json( (SELECT l FROM (SELECT 'name' as type, row_to_json( (SELECT l2 FROM (SELECT 'urn:ogc:def:crs:EPSG::'||Find_SRID('public', '@TABLE@', '@GEOM@') as name) as l2) ) as properties ) As l)   ) as crs, " + 
                    "array_to_json(array_agg(f)) As features " + 
                    "FROM (SELECT 'Feature' As type " + 
                    ", ST_AsGeoJSON(lg.@GEOM@, 0)::json As geometry " + 
                    ", row_to_json((SELECT l FROM ( SELECT @PROPS@ ) As l " + 
                    ")) As properties " +
                    "FROM @TABLE@ As lg @CLAUSE@ ) As f )  As fc;";
        
        

        var query = sql.replace(/@TABLE@/g, table)
                        .replace(/@GEOM@/g, geom)
                        .replace(/@PROPS@/g, cols2props)
                        .replace(/@CLAUSE@/g, !!(clause) ? clause : "" );

        console.log(query)

        client.query(query, vals, function(err, result) {
            res.send(result.rows[0].row_to_json);
            client.end()
            next();
        });
    });

}

var server = restify.createServer();

server.use(restify.CORS());

server.get('/:table', execute);
server.get('/:table/:prop/:id', byProp);

server.listen(8088, function() {
  console.log('%s listening at %s', server.name, server.url);
});