saving and loading db

This commit is contained in:
Dima Gerasimov 2019-04-30 13:10:12 +02:00
parent be2a9dffbd
commit 9545db4aaf

48
sql.py
View file

@ -6,6 +6,8 @@ import logging
from location import _load_locations, Location, get_logger
import sqlalchemy as sa # type: ignore
from kython import ichunks
# TODO wonder if possible to extract schema automatically?
def xx_obj():
@ -22,14 +24,7 @@ def make_schema(obj):
return [sa.Column(col, tp) for col, tp in obj._asdict().items()]
def main():
from kython import setup_logzero
setup_logzero(get_logger(), level=logging.DEBUG)
db_path = Path('test.sqlite')
if db_path.exists():
db_path.unlink()
def save_locs(db_path: Path):
db = sa.create_engine(f'sqlite:///{db_path}')
engine = db.connect() # TODO do I need to tear anything down??
meta = sa.MetaData(engine)
@ -39,16 +34,43 @@ def main():
table = sa.table('locations', *schema)
with Path('/L/tmp/loc/LocationHistory.json').open('r') as fo:
# locs = list(_load_locations(fo))
locs = list(islice(_load_locations(fo), 0, 30000))
# TODO fuck. do I really need to split myself??
# sqlalchemy.exc.OperationalError: (sqlite3.OperationalError) too many SQL variables
# TODO err wtf?? jsust 80000???
for chunk in ichunks(_load_locations(fo), 10000):
engine.execute(table.insert().values(chunk))
# TODO maintain order during insertion?
def load_locs(db_path: Path):
db = sa.create_engine(f'sqlite:///{db_path}')
engine = db.connect() # TODO do I need to tear anything down??
meta = sa.MetaData(engine)
schema = make_schema(xx_obj())
sa.Table('locations', meta, *schema)
meta.create_all()
table = sa.table('locations', *schema)
return engine.execute(table.select()).fetchall()
def main():
from kython import setup_logzero
setup_logzero(get_logger(), level=logging.DEBUG)
db_path = Path('test2.sqlite')
# if db_path.exists():
# db_path.unlink()
locs = [Location(**d) for d in load_locs(db_path)][:10]
print(locs)
# TODO fuck. do I really need to split myself??
# sqlalchemy.exc.OperationalError: (sqlite3.OperationalError) too many SQL variables
# TODO is it quicker to insert anyway? needs unique policy
engine.execute(table.insert().values(locs))
# ok, very nice. the whold db is just 4mb now
if __name__ == '__main__':
main()