#promise-pg

Q promises wrapper for the node.js PostgreSQL client 'pg'.

Install

$ npm install promise-pg

Examples

Basic access

Basic Usage.

var pg = require("promise-pg");
pg.connect("postgres://example:1234@localhost:5432/example").spread(function(client, done) {
    var query = client.query({
        text: "select * from users",
        buffer: true //if set to true, adds all the rows to the result object available on the rows property on the promise resolve value
    }).promise.then(
              function(result) { console.log(result); }, //rowCount etc
              function(err) { throw err; },
              function(user) {} //for each row
          ).finally(done);
}).done();

Basic example

Transactions

When using transactions you only need to specify a function that will be executed when the connection is within the transaction, your function returns a promise objects, if it is resolved the transaction is commited, if it is rejected the transaction is rolled back.

var pg = require("promise-pg");
var Q = require("q");
pg.connect("postgres://example:1234@localhost:5432/example").spread(function(client, done) {
    var INSERT = "INSERT INTO users(name, t_birth, country) VALUES ($1, $2, $3);";
    console.log("Transaction I:")
    var trans = client.transaction(function() {
        //This code runs in a transaction and should return a promise object, that when resolved the transaction is committed
        //But when rejected the transaction is rolled back.
        return Q.all([
            {
                text: INSERT,
                values: ["Jake1", "now()", "Oo"]
            },
            {
                text: INSERT,
                values: ["Cake2", null, "Küche"]
            },
            {
                text: INSERT,
                values: ["Mike3", "now()", null]
            }
        ].map(function(q) {
            return client.query(q).promise;
        }));
    }).then(function() {
            console.log("Good - Committed Transaction I."); //This will happen
        }, function(err) {
            console.log("Bad - Rolled back Transaction I.", err);
        }); //Not returning the connection to the pool yet


    trans.finally(function() { //after this transaction
        client.transaction(function() {
            //This code runs in a transaction and should return a promise object, that when resolved the transaction is committed
            //But when rejected the transaction is rolled back.

            return Q.all([
                {
                    text: INSERT,
                    values: ["Jake", "now()", "Oo"]
                },
                {
                    text: INSERT, //Bad, name is NOT NULL
                    values: [null, null, "Küche"]
                },
                {
                    text: INSERT,
                    values: ["Mike", "now()", null]
                }
            ].map(function(q) {
                return  client.query(q).promise;
            }));
        }).then(function() {
                console.log("Bad - Committed Transaction II."); //Cannot commit due to bad name
            }, function(err) {
                console.log("Good - Rolled back Transaction II.", err.message);
            }).finally(done).done();
    });
}).done();

Contributing

We appreciate any contributions!

If you need help getting the package to run, please feel free to message me .

License

Apache 2.0 License