Source code for pudl.load.sqlite

"""Load PUDL data into an SQLite database."""

import logging
import sys
from sqlite3 import Connection as SQLite3Connection
from sqlite3 import sqlite_version
from typing import Dict

import pandas as pd
import sqlalchemy as sa
from packaging import version
from sqlalchemy.exc import IntegrityError

from pudl.helpers import find_foreign_key_errors
from pudl.metadata.classes import Package

[docs]logger = logging.getLogger(__name__)
[docs]def dfs_to_sqlite( dfs: Dict[str, pd.DataFrame], engine: sa.engine.Engine, check_foreign_keys: bool = True, check_types: bool = True, check_values: bool = True, ) -> None: """Load a dictionary of dataframes into the PUDL DB.""" # This magic makes SQLAlchemy tell SQLite to check foreign key constraints # whenever we insert data into thd database, which it doesn't do by default @sa.event.listens_for(sa.engine.Engine, "connect") def _set_sqlite_pragma(dbapi_connection, connection_record): if isinstance(dbapi_connection, SQLite3Connection): cursor = dbapi_connection.cursor() cursor.execute( f"PRAGMA foreign_keys={'ON' if check_foreign_keys else 'OFF'};") cursor.close() bad_sqlite_version = ( version.parse(sqlite_version) < version.parse(MINIMUM_SQLITE_VERSION) ) if bad_sqlite_version and check_types: check_types = False logger.warning( f"Found SQLite {sqlite_version} which is less than " f"the minimum required version {MINIMUM_SQLITE_VERSION} " "As a result, data type constraint checking has been disabled." ) # Generate a SQLAlchemy MetaData object from dataframe names: md = Package.from_resource_ids(dfs).to_sql( check_types=check_types, check_values=check_values, ) # Delete any existing tables, and create them anew: md.drop_all(engine) md.create_all(engine) # Load any tables that exist in our dictionary of dataframes into the # corresponding table in the newly create database: for table in md.sorted_tables:"Loading {} into PUDL SQLite DB.") try: dfs[].to_sql(, engine, if_exists="append", index=False, dtype={ c.type for c in table.columns}, ) except IntegrityError as err: sys.exit(1)