Methods
allocateIds(key, options, callback)
Generate IDs without creating entities.
Parameters:
| Name | Type | Description | ||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
key |
Key |
The key object to complete. |
||||||||||||||||
options |
number | object |
Either the number of IDs to allocate or an options object for further customization of the request. Properties
|
||||||||||||||||
callback |
function |
The callback function. Properties
|
Example
const incompleteKey = datastore.key(['Company']);
//-
// The following call will create 100 new IDs from the Company kind, which
// exists under the default namespace.
//-
datastore.allocateIds(incompleteKey, 100, (err, keys) => {});
//-
// Or, if you're using a transaction object.
//-
const transaction = datastore.transaction();
transaction.run((err) => {
if (err) {
// Error handling omitted.
}
transaction.allocateIds(incompleteKey, 100, (err, keys) => {
if (err) {
// Error handling omitted.
}
transaction.commit((err) => {
if (!err) {
// Transaction committed successfully.
}
});
});
});
//-
// You may prefer to create IDs from a non-default namespace by providing
an
// incomplete key with a namespace. Similar to the previous example, the
call
// below will create 100 new IDs, but from the Company kind that exists
under
// the "ns-test" namespace.
//-
const incompleteKey = datastore.key({
namespace: 'ns-test',
path: ['Company']
});
function callback(err, keys, apiResponse) {}
datastore.allocateIds(incompleteKey, 100, callback);
//-
// Returns a Promise if callback is omitted.
//-
datastore.allocateIds(incompleteKey, 100).then((data) => {
const keys = data[0];
const apiResponse = data[1];
});createReadStream(keys, optionsopt)
Retrieve the entities as a readable object stream.
Parameters:
| Name | Type | Attributes | Description |
|---|---|---|---|
keys |
Key | Array.<Key> |
Datastore key object(s). |
|
options |
object |
<optional> |
Optional configuration. See Datastore#get for a complete list of options. |
Throws:
-
If at least one Key object is not provided.
- Type
- Error
Example
const keys = [
datastore.key(['Company', 123]),
datastore.key(['Product', 'Computer'])
];
datastore.createReadStream(keys)
.on('error', (err) => {})
.on('data', (entity) => {
// entity is an entity object.
})
.on('end', () => {
// All entities retrieved.
});delete(key, gaxOptionsopt, callback)
Delete all entities identified with the specified key(s).
Parameters:
| Name | Type | Attributes | Description | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
key |
Key | Array.<Key> |
Datastore key object(s). |
|||||||||||||
gaxOptions |
object |
<optional> |
Request configuration options, outlined here: https://googleapis.github.io/gax-nodejs/global.html#CallOptions. |
||||||||||||
callback |
function |
The callback function. Properties
|
Example
const key = datastore.key(['Company', 123]);
datastore.delete(key, (err, apiResp) => {});
//-
// Or, if you're using a transaction object.
//-
const transaction = datastore.transaction();
transaction.run((err) => {
if (err) {
// Error handling omitted.
}
transaction.delete(key);
transaction.commit((err) => {
if (!err) {
// Transaction committed successfully.
}
});
});
//-
// Delete multiple entities at once.
//-
datastore.delete([
datastore.key(['Company', 123]),
datastore.key(['Product', 'Computer'])
], (err, apiResponse) => {});
//-
// Returns a Promise if callback is omitted.
//-
datastore.delete().then((data) => {
const apiResponse = data[0];
});get(keys, optionsopt, callback)
Retrieve the entities identified with the specified key(s) in the current transaction. Get operations require a valid key to retrieve the key-identified entity from Datastore.
Parameters:
| Name | Type | Attributes | Description | ||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
keys |
Key | Array.<Key> |
Datastore key object(s). |
|||||||||||||||||||||
options |
object |
<optional> |
Optional configuration. Properties
|
||||||||||||||||||||
callback |
function |
The callback function. Properties
|
Throws:
-
If at least one Key object is not provided.
- Type
- Error
Example
//-
// Get a single entity.
//-
const key = datastore.key(['Company', 123]);
datastore.get(key, (err, entity) => {});
//-
// Or, if you're using a transaction object.
//-
const transaction = datastore.transaction();
transaction.run((err) => {
if (err) {
// Error handling omitted.
}
transaction.get(key, (err, entity) => {
if (err) {
// Error handling omitted.
}
transaction.commit((err) => {
if (!err) {
// Transaction committed successfully.
}
});
});
});
//-
// Get multiple entities at once with a callback.
//-
const keys = [
datastore.key(['Company', 123]),
datastore.key(['Product', 'Computer'])
];
datastore.get(keys, (err, entities) => {});
//-
// Below is how to update the value of an entity with the help of the
// `save` method.
//-
datastore.get(key, (err, entity) => {
if (err) {
// Error handling omitted.
}
entity.newValue = true;
datastore.save({
key: key,
data: entity
}, (err) => {});
});
//-
// Returns a Promise if callback is omitted.
//-
datastore.get(keys).then((data) => {
const entities = data[0];
});insert(entities, callback)
Maps to Datastore#save, forcing the method to be insert.
Parameters:
| Name | Type | Description | ||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
entities |
object | Array.<object> |
Datastore key object(s). Properties
|
||||||||||||||||
callback |
function |
The callback function. Properties
|
merge(entities, callback)
Merge the specified object(s). If a key is incomplete, its associated object
is inserted and the original Key object is updated to contain the generated ID.
For example, if you provide an incomplete key (one without an ID),
the request will create a new entity and have its ID automatically assigned.
If you provide a complete key, the entity will be get the data from datastore
and merge with the data specified.
By default, all properties are indexed. To prevent a property from being
included in all indexes, you must supply an excludeFromIndexes array.
Maps to Datastore#save, forcing the method to be merge.
Parameters:
| Name | Type | Description | ||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
entities |
object | Array.<object> |
Datastore key object(s). Properties
|
||||||||||||||||
callback |
function |
The callback function. Properties
|
runQuery(query, optionsopt, callbackopt)
Datastore allows you to query entities by kind, filter them by property filters, and sort them by a property name. Projection and pagination are also supported.
The query is run, and the results are returned as the second argument to your callback. A third argument may also exist, which is a query object that uses the end cursor from the previous query as the starting cursor for the next query. You can pass that object back to this method to see if more results exist.
Parameters:
| Name | Type | Attributes | Description | ||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
query |
Query |
Query object. |
|||||||||||||||||||||||||||||
options |
object |
<optional> |
Optional configuration. Properties
|
||||||||||||||||||||||||||||
callback |
function |
<optional> |
The callback function. If omitted, a readable stream instance is returned. Properties
|
Example
//-
// Where you see `transaction`, assume this is the context that's relevant
to
// your use, whether that be a Datastore or a Transaction object.
//-
const query = datastore.createQuery('Lion');
datastore.runQuery(query, (err, entities, info) => {
// entities = An array of records.
// Access the Key object for an entity.
const firstEntityKey = entities[0][datastore.KEY];
});
//-
// Or, if you're using a transaction object.
//-
const transaction = datastore.transaction();
transaction.run((err) => {
if (err) {
// Error handling omitted.
}
transaction.runQuery(query, (err, entities) => {
if (err) {
// Error handling omitted.
}
transaction.commit((err) => {
if (!err) {
// Transaction committed successfully.
}
});
});
});
//-
// A keys-only query returns just the keys of the result entities instead
of
// the entities themselves, at lower latency and cost.
//-
const keysOnlyQuery = datastore.createQuery('Lion').select('__key__');
datastore.runQuery(keysOnlyQuery, (err, entities) => {
const keys = entities.map((entity) => {
return entity[datastore.KEY];
});
});
//-
// Returns a Promise if callback is omitted.
//-
datastore.runQuery(query).then((data) => {
const entities = data[0];
});runQueryStream(query, optionsopt)
Get a list of entities as a readable object stream.
See Datastore#runQuery for a list of all available options.
Parameters:
| Name | Type | Attributes | Description | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
query |
Query |
Query object. |
|||||||||
options |
object |
<optional> |
Optional configuration. Properties
|
Example
datastore.runQueryStream(query)
.on('error', console.error)
.on('data', (entity) => {
// Access the Key object for this entity.
const key = entity[datastore.KEY];
})
.on('info', (info) => {})
.on('end', () => {
// All entities retrieved.
});
//-
// If you anticipate many results, you can end a stream early to prevent
// unnecessary processing and API requests.
//-
datastore.runQueryStream(query)
.on('data', (entity) => {
this.end();
});save(entities, gaxOptionsopt, callback)
Insert or update the specified object(s). If a key is incomplete, its associated object is inserted and the original Key object is updated to contain the generated ID.
This method will determine the correct Datastore method to execute
(upsert, insert, or update) by using the key(s) provided. For
example, if you provide an incomplete key (one without an ID), the request
will create a new entity and have its ID automatically assigned. If you
provide a complete key, the entity will be updated with the data specified.
By default, all properties are indexed. To prevent a property from being
included in all indexes, you must supply an excludeFromIndexes array.
To prevent large properties from being included in all indexes, you must supply
excludeLargeProperties: true.
See below for an example.
Parameters:
| Name | Type | Attributes | Description | ||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
entities |
object | Array.<object> |
Datastore key object(s). Properties
|
|||||||||||||||||||||||||
gaxOptions |
object |
<optional> |
Request configuration options, outlined here: https://googleapis.github.io/gax-nodejs/global.html#CallOptions. |
||||||||||||||||||||||||
callback |
function |
The callback function. Properties
|
Throws:
-
If an unrecognized method is provided.
- Type
- Error
Example
//-
// Save a single entity.
//
// Notice that we are providing an incomplete key. After saving, the
original
// Key object used to save will be updated to contain the path with its
// generated ID.
//-
const key = datastore.key('Company');
const entity = {
key: key,
data: {
rating: '10'
}
};
datastore.save(entity, (err) => {
console.log(key.path); // [ 'Company', 5669468231434240 ]
console.log(key.namespace); // undefined
});
//-
// Save a single entity using a provided name instead of auto-generated ID.
//
// Here we are providing a key with name instead of an ID. After saving,
the
// original Key object used to save will be updated to contain the path
with
// the name instead of a generated ID.
//-
const key = datastore.key(['Company', 'donutshack']);
const entity = {
key: key,
data: {
name: 'DonutShack',
rating: 8
}
};
datastore.save(entity, (err) => {
console.log(key.path); // ['Company', 'donutshack']
console.log(key.namespace); // undefined
});
//-
// Save a single entity with a provided namespace. Namespaces allow for
// multitenancy. To read more about this, see
// [the Datastore docs on key concepts](https://goo.gl/M1LUAu).
//
// Here we are providing a key with namespace.
//-
const key = datastore.key({
namespace: 'my-namespace',
path: ['Company', 'donutshack']
});
const entity = {
key: key,
data: {
name: 'DonutShack',
rating: 8
}
};
datastore.save(entity, (err) => {
console.log(key.path); // ['Company', 'donutshack']
console.log(key.namespace); // 'my-namespace'
});
//-
// Save different types of data, including ints, doubles, dates, booleans,
// blobs, and lists.
//
// Notice that we are providing an incomplete key. After saving, the
original
// Key object used to save will be updated to contain the path with its
// generated ID.
//-
const key = datastore.key('Company');
const entity = {
key: key,
data: {
name: 'DonutShack',
rating: datastore.int(10),
worth: datastore.double(123456.78),
location: datastore.geoPoint({
latitude: 40.6894,
longitude: -74.0447
}),
numDonutsServed: 45,
founded: new Date('Tue May 12 2015 15:30:00 GMT-0400 (EDT)'),
isStartup: true,
donutEmoji: Buffer.from('\uD83C\uDF69'),
keywords: [
'donut',
'coffee',
'yum'
]
}
};
datastore.save(entity, (err, apiResponse) => {});
//-
// Use an array, `excludeFromIndexes`, to exclude properties from indexing.
// This will allow storing string values larger than 1500 bytes.
//-
const entity = {
key: datastore.key('Company'),
excludeFromIndexes: [
'description',
'embeddedEntity.description',
'arrayValue[]',
'arrayValue[].description'
],
data: {
description: 'Long string (...)',
embeddedEntity: {
description: 'Long string (...)'
},
arrayValue: [
'Long string (...)',
{
description: 'Long string (...)'
}
]
}
};
datastore.save(entity, (err, apiResponse) => {});
//-
// Use boolean `excludeLargeProperties`, to auto exclude Large properties from indexing.
// This will allow storing string values larger than 1500 bytes.
//-
const entity = {
key: datastore.key('Company'),
data: {
description: 'Long string (...)',
embeddedEntity: {
description: 'Long string (...)'
},
arrayValue: [
'Long string (...)',
{
description: 'Long string (...)'
}
]
},
excludeLargeProperties: true
};
datastore.save(entity, (err, apiResponse) => {});
//-
// Save multiple entities at once.
//-
const companyKey = datastore.key(['Company', 123]);
const productKey = datastore.key(['Product', 'Computer']);
const entities = [
{
key: companyKey,
data: {
HQ: 'Dallas, TX'
}
},
{
key: productKey,
data: {
vendor: 'Dell'
}
}
];
datastore.save(entities, (err, apiResponse) => {});
//-
// Explicitly attempt to 'insert' a specific entity.
//-
const userKey = datastore.key(['User', 'chilts']);
const entity = {
key: userKey,
method: 'insert',
data: {
fullName: 'Andrew Chilton'
}
};
datastore.save(entity, (err, apiResponse) => {});
//-
// Returns a Promise if callback is omitted.
//-
datastore.save(entity).then((data) => {
const apiResponse = data[0];
});update(entities, callback)
Maps to Datastore#save, forcing the method to be update.
Parameters:
| Name | Type | Description | ||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
entities |
object | Array.<object> |
Datastore key object(s). Properties
|
||||||||||||||||
callback |
function |
The callback function. Properties
|
upsert(entities, callback)
Maps to Datastore#save, forcing the method to be upsert.
Parameters:
| Name | Type | Description | ||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
entities |
object | Array.<object> |
Datastore key object(s). Properties
|
||||||||||||||||
callback |
function |
The callback function. Properties
|