Bigtable

<caption>Create a client that uses <a
href="https://cloud.google.com/docs/authentication/production#providing_credentials_to_your_application">Application
Default Credentials (ADC)</a>:</caption> const Bigtable =
require('@google-cloud/bigtable'); const bigtable = new Bigtable();

<caption>Create a client with <a
href="https://cloud.google.com/docs/authentication/production#obtaining_and_providing_service_account_credentials_manually">explicit
credentials</a>:</caption> const Bigtable =
require('@google-cloud/bigtable'); const bigtable = new Bigtable({ projectId:
'your-project-id', keyFilename: '/path/to/keyfile.json'
});

//<h4> The Bigtable Emulator</h4>
//
// Make sure you have the <a href="https://cloud.google.com/sdk/downloads">
// gcloud SDK installed</a>, then run:
//
// <pre>
//   $ gcloud beta emulators bigtable start
// </pre>
//
// Before running your Node.js app, set the environment variables that this
// library will look for to connect to the emulator:
//
// <pre>
//   $ $(gcloud beta emulators bigtable env-init)
// </pre>
//-

//-
// <h4>Creating a Bigtable Instance and Cluster</h4>
//
// Before you create your table, you first need to create a Bigtable Instance
// and cluster for the table to be served from.
//-
const Bigtable = require('@google-cloud/bigtable');
const bigtable = new Bigtable();

const callback = function(err, instance, operation) {
  operation
    .on('error', console.log)
    .on('complete', function() {
      // `instance` is your newly created Instance object.
    });
};

const instance = bigtable.instance('my-instance');

instance.create({
  clusters: [
    {
      id: 'my-cluster',
      location: 'us-central1-b',
      nodes: 3
    }
  ]
}, callback);

//-
// This can also be done from either the Google Cloud Platform Console or the
// `gcloud` cli tool. Please refer to the
// <a href="https://cloud.google.com/bigtable/docs/creating-instance">
// official Bigtable documentation</a> for more information.
//-

//-
// <h4>Creating Tables</h4>
//
// After creating your instance and enabling the Bigtable APIs, you are now
// ready to create your table with {@link Instance#createTable}.
//-
instance.createTable('prezzy', function(err, table) {
  // `table` is your newly created Table object.
});

//-
// <h4>Creating Column Families</h4>
//
// Column families are used to group together various pieces of data within
// your table. You can think of column families as a mechanism to categorize
// all of your data.
//
// We can create a column family with {@link Table#createFamily}.
//-
const table = instance.table('prezzy');

table.createFamily('follows', function(err, family) {
  // `family` is your newly created Family object.
});

//-
// It is also possible to create your column families when creating a new
// table.
//-
const options = {
  families: ['follows']
};

instance.createTable('prezzy', options, function(err, table) {});

//-
// <h4>Creating Rows</h4>
//
// New rows can be created within your table using
// {@link Table#insert}. You must provide a unique key for each row
// to be inserted, this key can then be used to retrieve your row at a later
// time.
//
// With Bigtable, all columns have a unique id composed of a column family
// and a column qualifier. In the example below `follows` is the column
// family and `tjefferson` is the column qualifier. Together they could be
// referred to as `follows:tjefferson`.
//-
const rows = [
  {
    key: 'wmckinley',
    data: {
      follows: {
        tjefferson: 1
      }
    }
  }
];

table.insert(rows, function(err) {
  if (!err) {
    // Your rows were successfully inserted.
  }
});

//-
// <h4>Retrieving Rows</h4>
//
// If you're anticipating a large number of rows to be returned, we suggest
// using the {@link Table#getRows} streaming API.
//-
table.createReadStream()
  .on('error', console.error)
  .on('data', function(row) {
    // `row` is a Row object.
  });

//-
// If you're not anticpating a large number of results, a callback mode
// is also available.
//-
const callback = function(err, rows) {
  // `rows` is an array of Row objects.
};

table.getRows(callback);

//-
// A range of rows can be retrieved by providing `start` and `end` row keys.
//-
const options = {
  start: 'gwashington',
  end: 'wmckinley'
};

table.getRows(options, callback);

//-
// Retrieve an individual row with {@link Row#get}.
//-
const row = table.row('alincoln');

row.get(function(err) {
  // `row.data` is now populated.
});

//-
// <h4>Accessing Row Data</h4>
//
// When retrieving rows, upon success the `row.data` property will be
// populated by an object. That object will contain additional objects
// for each family in your table that the row has data for.
//
// By default, when retrieving rows, each column qualifier will provide you
// with all previous versions of the data. So your `row.data` object could
// resemble the following.
//-
// {
//   follows: {
//     wmckinley: [
//       {
//         value: 1,
//         timestamp: 1466017315951
//       }, {
//         value: 2,
//         timestamp: 1458619200000
//       }
//     ]
//   }
// }

//-
// The `timestamp` field can be used to order cells from newest to oldest.
// If you only wish to retrieve the most recent version of the data, you
// can specify the number of cells with a {@link Filter} object.
//-
const filter = [
  {
    column: {
      cellLimit: 1
    }
  }
];

table.getRows({
  filter: filter
}, callback);

//-
// <h4>Deleting Row Data</h4>
//
// We can delete all of an individual row's cells using
// {@link Row#delete}.
//-
const callback = function(err) {
  if (!err) {
    // All cells for this row were deleted successfully.
  }
};

row.delete(callback);

//-
// To delete a specific set of cells, we can provide an array of
// column families and qualifiers.
//-
const cells = [
  'follows:gwashington',
  'traits'
];

row.delete(cells, callback);

//-
// <h4>Deleting Rows</h4>
//
// If you wish to delete multiple rows entirely, we can do so with
// {@link Table#deleteRows}. You can provide this method with a
// row key prefix.
//-
const options = {
  prefix: 'gwash'
};

table.deleteRows(options, function(err) {
  if (!err) {
    // Rows were deleted successfully.
  }
});

//-
// If you omit the prefix, you can delete all rows in your table.
//-
table.deleteRows(function(err) {
  if (!err) {
    // All rows were deleted successfully.
  }
});