Members

defaultOptions

transaction.js, line 333

Returns the default options for a transaction.

EVENTS

transaction.js, line 375

All events transactions may emit. POST_COMMIT: When a transaction is committed. Do clean up, summery, post process here. TX_FAILED: When a transaction failed permanently (either by failing all retries, or getting a non-retryable error). Handler has the signature of (error) => {}.

Methods

async, static run(optionsopt, func)

transaction.js, line 973

Runs a function in transaction, using specified parameters. If a non-retryable error is thrown while running the transaction, it will be re-raised.

Parameters:

Name	Type	Attributes	Description
options	TransactionOptions	<optional>
func	function		the closure to run.

Example

// Can be called in 2 ways:
Transaction.run(async (tx) => {
  // Do something
})

// Or
Transaction.run({ retryCount: 2 }, async (tx) => {
  // Do something
})

async __batchGetItems(keys, params)

transaction.js, line 490

Gets multiple items using DynamoDB's batchGetItems API.

Parameters:

Name	Type	Description
keys	Array.<Key>	A list of keys to get.
params	GetParams	Params used to get items, all items will be fetched using the same params.

async __getItem(key, params)

transaction.js, line 398

Get an item using DynamoDB's getItem API.

Parameters:

Name	Type	Description
key	Key	A key for the item
params	GetParams	Params for how to get the item

async __transactGetItems(keys, params)

transaction.js, line 433

Gets multiple items using DynamoDB's transactGetItems API.

Parameters:

Name	Type	Description
keys	Array.<Key>	A list of keys to get.
params	GetParams	Params used to get items, all items will be fetched using the same params.

create(Cls, data)

transaction.js, line 799

Creates a model without accessing DB. Write will make sure the item does not exist.

Parameters:

Name	Type	Description
Cls	Model	A Model class.
data	CompositeID | Object	A superset of CompositeID of the model, plus any data for Fields on the Model.

createOrPut(Cls, original, updated)

transaction.js, line 755

Creates or puts an item without reading from DB. It differs from update in that: a) If item doesn't exists, a new item is created in DB b) If item does exists, fields present locally will overwrite values in DB, fields absent locally will be removed from DB.

Parameters:

Name	Type	Description
Cls	Class	The model's class.
original	CompositeID | Object	A superset of CompositeID, field's values. Non-key values are used for conditional locking
updated	Object	Final values for the model. Values for every field in the model must be provided. Fields with `undefined` value will be removed from DB.

delete(…args)

transaction.js, line 813

Deletes model(s) from database. If a model is read from database, but it did not exist when deleting the item, an exception is raised.

Parameters:

Name	Type	Attributes	Description
args	List.<(Key|Model)>	<repeatable>	Keys and Models

enableModelCache()

transaction.js, line 882

Enables model cache

async get(Cls, key, paramsopt)

transaction.js, line 605

Fetches model(s) from database. This method supports 3 different signatures. get(Cls, keyOrDataValues, params) get(Key|Data, params) get([Key|Data], params) When only one items is fetched, DynamoDB's getItem API is called. Must use a Key when createIfMissing is not true, and Data otherwise. When a list of items is fetched: If inconsistentRead is false (the default), DynamoDB's transactGetItems API is called for a strongly consistent read. Transactional reads will be slower than batched reads. If inconsistentRead is true, DynamoDB's batchGetItems API is called. Batched fetches are more efficient than calling get with 1 key many times, since there is less HTTP request overhead. Batched fetches is faster than transactional fetches, but provides a weaker consistency.

Parameters:

Name	Type	Attributes	Description
Cls	Class		a Model class.
key	String | CompositeID		Key or keyValues
params	GetParams	<optional>

Returns:

- Model(s) associated with provided key

getModelDiffs()

transaction.js, line 985

Return before and after snapshots of all relevant models.

makeReadOnly()

transaction.js, line 877

Marks a transaction as read-only.

query(ModelCls)

transaction.js, line 847

Create a handle for applications to query DB items.

Parameters:

Name	Type	Description
ModelCls	Model	A model class.
params.options	IteratorOptions	Iterator options

Returns:

- Query handle. See __DBIterator for details.

scan(ModelCls)

transaction.js, line 833

Create a handle for applications to scan DB items.

Parameters:

Name	Type	Description
ModelCls	Model	A model class.
params.options	IteratorOptions	Iterator options

Returns:

- Scan handle. See __DBIterator for details.

update(Cls, original, updated)

transaction.js, line 708

Updates an item without reading from DB. If the item doesn't exist in DB, ConditionCheckFailure will be thrown.

Parameters:

Name	Type	Description
Cls	Class	The model's class.
original	CompositeID | Object	A superset of CompositeID, field's values. Used as conditions for the update
updated	Object	Updated fields for the item, without CompositeID fields.