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Transaction

The transaction object is used to identify a running transaction. It is created by calling Sequelize.transaction(). To run a query under a transaction, you should pass the transaction in the options object.

See:

Sequelize.transaction

Static Member Summary

Static Public Members
public static get	ISOLATION_LEVELS: {"READ_UNCOMMITTED": string, "READ_COMMITTED": string, "REPEATABLE_READ": string, "SERIALIZABLE": string} Isolation levels can be set per-transaction by passing `options.isolationLevel` to `sequelize.transaction`.
public static get	LOCK: object: {"UPDATE": string, "SHARE": string, "KEY_SHARE": string, "NO_KEY_UPDATE": string} Possible options for row locking.
public static get	TYPES: {"DEFERRED": string, "IMMEDIATE": string, "EXCLUSIVE": string} Types can be set per-transaction by passing `options.type` to `sequelize.transaction`.

Constructor Summary

Public Constructor
public	constructor(sequelize: Sequelize, options: object) Creates a new transaction instance

Member Summary

Public Members
public get	LOCK: * Please see Transaction.LOCK

Method Summary

Public Methods
public	afterCommit(fn: Function) A hook that is run after a transaction is committed
public	async commit(): Promise Commit the transaction
public	async forceCleanup() Kills the connection this transaction uses.
public	async prepareEnvironment(useCLS: boolean): Promise Called to acquire a connection to use and set the correct options on the connection.
public	async rollback(): Promise Rollback (abort) the transaction

Static Public Members

public static get ISOLATION_LEVELS: {"READ_UNCOMMITTED": string, "READ_COMMITTED": string, "REPEATABLE_READ": string, "SERIALIZABLE": string} source

Isolation levels can be set per-transaction by passing options.isolationLevel to sequelize.transaction. Sequelize uses the default isolation level of the database, you can override this by passing options.isolationLevel in Sequelize constructor options.

Pass in the desired level as the first argument:

Properties:

Name	Type	Attribute	Description
READ_UNCOMMITTED	*
READ_COMMITTED	*
REPEATABLE_READ	*
SERIALIZABLE	*

Example:

try {
  const result = await sequelize.transaction({isolationLevel: Sequelize.Transaction.ISOLATION_LEVELS.SERIALIZABLE}, transaction => {
    // your transactions
  });
  // transaction has been committed. Do something after the commit if required.
} catch(err) {
  // do something with the err.
}

public static get LOCK: object: {"UPDATE": string, "SHARE": string, "KEY_SHARE": string, "NO_KEY_UPDATE": string} source

Possible options for row locking. Used in conjunction with find calls:

Properties:

Name	Type	Description
UPDATE	*
SHARE	*
KEY_SHARE	*	Postgres 9.3+ only
NO_KEY_UPDATE	*	Postgres 9.3+ only

Return:

object

Return Properties:

Name	Type	Description
UPDATE	*
SHARE	*
KEY_SHARE	*	Postgres 9.3+ only
NO_KEY_UPDATE	*	Postgres 9.3+ only

Example:

// t1 is a transaction
Model.findAll({
  where: ...,
  transaction: t1,
  lock: t1.LOCK...
});

Postgres also supports specific locks while eager loading by using OF:

UserModel.findAll({
  where: ...,
  include: [TaskModel, ...],
  transaction: t1,
  lock: {
    level: t1.LOCK...,
    of: UserModel
  }
});

# UserModel will be locked but TaskModel won't!

You can also skip locked rows:

// t1 is a transaction
Model.findAll({
  where: ...,
  transaction: t1,
  lock: true,
  skipLocked: true
});
# The query will now return any rows that aren't locked by another transaction

public static get TYPES: {"DEFERRED": string, "IMMEDIATE": string, "EXCLUSIVE": string} source

Types can be set per-transaction by passing options.type to sequelize.transaction. Default to DEFERRED but you can override the default type by passing options.transactionType in new Sequelize. Sqlite only.

Pass in the desired level as the first argument:

Properties:

Name	Type	Attribute	Description
DEFERRED	*
IMMEDIATE	*
EXCLUSIVE	*

Example:

try {
  await sequelize.transaction({ type: Sequelize.Transaction.TYPES.EXCLUSIVE }, transaction => {
     // your transactions
  });
  // transaction has been committed. Do something after the commit if required.
} catch(err) {
  // do something with the err.
}

Public Constructors

public constructor(sequelize: Sequelize, options: object) source

Creates a new transaction instance

Params:

Name	Type	Attribute	Description
sequelize	Sequelize		A configured sequelize Instance
options	object		An object with options
options.type	string	optional	Sets the type of the transaction. Sqlite only
options.isolationLevel	string	optional	Sets the isolation level of the transaction.
options.deferrable	string	optional	Sets the constraints to be deferred or immediately checked. PostgreSQL only

Public Members

public get LOCK: * source

Please see Transaction.LOCK

Public Methods

public afterCommit(fn: Function) source

A hook that is run after a transaction is committed

Params:

Name	Type	Attribute	Description
fn	Function		A callback function that is called with the committed transaction

public async commit(): Promise source

Commit the transaction

Return:

Promise

public async forceCleanup() source

Kills the connection this transaction uses. Used as a last resort, for instance because COMMIT or ROLLBACK resulted in an error and the transaction is left in a broken state, and releasing the connection to the pool would be dangerous.

public async prepareEnvironment(useCLS: boolean): Promise source

Called to acquire a connection to use and set the correct options on the connection. We should ensure all of the environment that's set up is cleaned up in cleanup() below.

Params:

Name	Type	Attribute	Description
useCLS	boolean		Defaults to true: Use CLS (Continuation Local Storage) with Sequelize. With CLS, all queries within the transaction callback will automatically receive the transaction object.

Return:

Promise

public async rollback(): Promise source

Rollback (abort) the transaction

Return:

Promise