transact

transact<T>(fn): Promise<T>

Defined in: .work/repos/edinburgh/src/edinburgh.ts:137

Executes a function within a database transaction context.

Loading models (also through links in other models) and changing models can only be done from within a transaction.

Transactions have a consistent view of the database, and changes made within a transaction are isolated from other transactions until they are committed. In case a commit clashes with changes made by another transaction, the transaction function will automatically be re-executed up to 6 times.

Type Parameters

T

T

The return type of the transaction function.

Parameters

fn

() => T

The function to execute within the transaction context. Receives a Transaction instance.

Returns

Promise<T>

A promise that resolves with the function’s return value.

Throws

With code “RACING_TRANSACTION” if the transaction fails after retries due to conflicts.

Throws

With code “TXN_LIMIT” if maximum number of transactions is reached.

Throws

With code “LMDB-{code}” for LMDB-specific errors.

Example

const paid = await E.transact(() => {
  const user = User.get("john_doe");
  if (user.credits > 0) {
    user.credits--;
    return true;
  }
  return false;
});

// Transaction with automatic retry on conflicts
await E.transact(() => {
  const counter = Counter.get("global") || new Counter({id: "global", value: 0});
  counter.value++;
});