anki/pylib/anki/dbproxy.py
2020-03-24 10:37:12 +10:00

91 lines
2.4 KiB
Python

# Copyright: Ankitects Pty Ltd and contributors
# License: GNU AGPL, version 3 or later; http://www.gnu.org/licenses/agpl.html
from __future__ import annotations
from typing import Any, Iterable, List, Optional, Sequence, Union
import anki
# DBValue is actually Union[str, int, float, None], but if defined
# that way, every call site needs to do a type check prior to using
# the return values.
ValueFromDB = Any
Row = Sequence[ValueFromDB]
ValueForDB = Union[str, int, float, None]
class DBProxy:
# Lifecycle
###############
def __init__(self, backend: anki.rsbackend.RustBackend, path: str) -> None:
self._backend = backend
self._path = path
self.mod = False
# Transactions
###############
def begin(self) -> None:
self._backend.db_begin()
def commit(self) -> None:
self._backend.db_commit()
def rollback(self) -> None:
self._backend.db_rollback()
# Querying
################
def _query(
self, sql: str, *args: ValueForDB, first_row_only: bool = False
) -> List[Row]:
# mark modified?
s = sql.strip().lower()
for stmt in "insert", "update", "delete":
if s.startswith(stmt):
self.mod = True
# fetch rows
return self._backend.db_query(sql, args, first_row_only)
# Query shortcuts
###################
def all(self, sql: str, *args: ValueForDB) -> List[Row]:
return self._query(sql, *args)
def list(self, sql: str, *args: ValueForDB) -> List[ValueFromDB]:
return [x[0] for x in self._query(sql, *args)]
def first(self, sql: str, *args: ValueForDB) -> Optional[Row]:
rows = self._query(sql, *args, first_row_only=True)
if rows:
return rows[0]
else:
return None
def scalar(self, sql: str, *args: ValueForDB) -> ValueFromDB:
rows = self._query(sql, *args, first_row_only=True)
if rows:
return rows[0][0]
else:
return None
# execute used to return a pysqlite cursor, but now is synonymous
# with .all()
execute = all
# Updates
################
def executemany(self, sql: str, args: Iterable[Sequence[ValueForDB]]) -> None:
self.mod = True
if isinstance(args, list):
list_args = args
else:
list_args = list(args)
self._backend.db_execute_many(sql, list_args)