Puts a transaction into a context and returns the new context with the transaction.

Creates an Initializer that performs a database migration by looking for sql files in the default directories.

Runs a migration with the sql files from the given directory.

Gets the current transaction from the context or nil, if the context does not contain a transaction.

Ends the given transaction.

Calls the given operation with the transaction that is currently stored in the context.

Creates a new transaction, puts it into the context and runs the given operation with the context and the transaction.