DB access

The DbAccess is the abstract base for access to a database. It’s a very simple interface, able to get records based on a DbRecordsSpec.

tablecache.db.RecordParser[DbRecord, Record]: collections.abc.Callable[[DbRecord], Record]: A function parsing a record from the DB into a custom data structure.

class tablecache.DbRecordsSpec

Base type for a specification of records in the DB.

__init__(*, record_parser=None)

Parameters:: record_parser (RecordParser | None) – An optional function that is applied to each record before it is returned. The default is to return the record as-is.

class tablecache.QueryArgsDbRecordsSpec

A specification of DB records via a query and args.

__init__(query, args, *, record_parser=None)

Parameters:

record_parser (RecordParser | None) – An optional function that is applied to each record before it is returned. The default is to return the record as-is.
query (str) –
args (tuple) –

class tablecache.DbAccess

A DB access abstraction.

Provides access to sets of records stored in the DB via a records spec that is up to the concrete implementation.

async get_record(records_spec)

Fetch a single record.

This is just a convenience shortcut around get_records().

If more than one record matches the spec, one of them is returned, but there is no guarantee which. :raise KeyError: If no record matches.

abstract async get_records(records_spec)

Asynchronously iterate over a subset of records.

Fetches records matching the given spec and yields them.