Getting Started:
CRUD Operations with NodeJS
Creating Objects In Riak KV
Pinging a Riak cluster sounds like a lot of fun, but eventually someone is going to want us to do productive work. Let’s create some data to save in Riak.
The Riak Node.js Client makes use of a RiakObject
class to encapsulate Riak
key/value objects. At the most basic, a RiakObject
is responsible for
identifying your object and for translating it into a format that can be easily
saved to Riak.
var async = require('async');
var people = [
{
emailAddress: "bashoman@riak.com",
firstName: "Riak",
lastName: "Man"
},
{
emailAddress: "johndoe@gmail.com",
firstName: "John",
lastName: "Doe"
}
];
var storeFuncs = [];
people.forEach(function (person) {
// Create functions to execute in parallel to store people
storeFuncs.push(function (async_cb) {
client.storeValue({
bucket: 'contributors',
key: person.emailAddress,
value: person
},
function(err, rslt) {
async_cb(err, rslt);
}
);
});
});
async.parallel(storeFuncs, function (err, rslts) {
if (err) {
throw new Error(err);
}
});
In this sample, we create a collection of Person
objects and then save each
Person
to Riak. Once again, we check the response from Riak.
Reading from Riak
Let’s find a person!
var logger = require('winston');
client.fetchValue({ bucket: 'contributors', key: 'bashoman@riak.com', convertToJs: true },
function (err, rslt) {
if (err) {
throw new Error(err);
} else {
var riakObj = rslt.values.shift();
var bashoman = riakObj.value;
logger.info("I found %s in 'contributors'", bashoman.emailAddress);
}
}
);
We use client.fetchValue
to retrieve an object from Riak. This returns an
array of RiakObject
objects which helpfully encapsulates the communication
with Riak.
After verifying that we’ve been able to communicate with Riak and that we have
a successful result, we use the value
property to get the object, which has
already been converted to a javascript object due to the use of convertToJs:
true
in the options.
Modifying Existing Data
Let’s say that Riak Man has decided to be known as Riak Man:
bashoman.FirstName = "Riak";
riakObj.setValue(bashoman);
client.storeValue({ value: riakObj }, function (err, rslt) {
if (err) {
throw new Error(err);
}
});
Updating an object involves modifying a RiakObject
then using
client.storeValue
to save the existing object.
Deleting Data
client.deleteValue({ bucket: 'contributors', key: 'johndoe@gmail.com' }, function (err, rslt) {
if (err) {
throw new Error(err);
}
});
Just like other operations, we check the results that have come back from Riak to make sure the object was successfully deleted.
The Riak Node.js Client has a lot of additional functionality that makes it easy to build rich, complex applications with Riak. Check out the documentation to learn more about working with the Riak Node.js Client and Riak.