patito.Database.as_query

Database.as_query(*, lazy=False, cache=False, ttl=None, model=None, **kwargs)

Execute the returned query string and return a polars dataframe.

Parameters:

  • lazy (bool) – If the result should be returned as a LazyFrame rather than a DataFrame. Allows more efficient reading from parquet caches if caching is enabled.

  • cache (Union[str, Path, bool]) – If queries should be cached in order to save time and costs. The cache will only be used if the exact same SQL string has been executed before. If the parameter is specified as True, a parquet file is created for each unique query string, and is located at: artifacts/query_cache/<function_name>/<query_md5_hash>.parquet If the a string or pathlib.Path object is provided, the given path will be used, but it must have a ‘.parquet’ file extension. Relative paths are interpreted relative to artifacts/query_cache/ in the workspace root. The given parquet path will be overwritten if the query string changes, so only the latest query string value will be cached.

  • ttl (Optional[timedelta]) – The Time to Live (TTL) of the cache specified as a datetime.timedelta object. When the cache becomes older than the specified TTL, the query will be re-executed on the next invocation of the query function and the cache will refreshed.

  • model (Optional[Type[Model]]) – An optional Patito model used to validate the content of the dataframe before return.

  • **kwargs (Any) – Connection parameters forwarded to sql_to_polars, for example db_params.

Return type:

Callable[[QueryConstructor[ParamSpec(P)]], DatabaseQuery[ParamSpec(P), Union[DataFrame, LazyFrame]]]

Returns:

A new function which returns a polars DataFrame based on the query specified by the original function’s return string.