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.

Transaction

Constructors

Properties

id: string
parent: null | Transaction
sequelize: Sequelize

Accessors

  • get ISOLATION_LEVELS(): typeof IsolationLevel

    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:

    Returns typeof IsolationLevel

    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.
    }

    use the IsolationLevel export

  • get LOCK(): typeof Lock

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

    Returns typeof Lock

    possible options for row locking

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

    UserModel will be locked but TaskModel won't!

    // 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

    use the Lock export

  • get TYPES(): typeof TransactionType

    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:

    Returns typeof TransactionType

    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.
    }

    use the TransactionType export

Methods

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

    Returns Promise<void>