Keep the rows of a relation matching a DuckDB SQL expression.
The expression can use the attributes (e.g. POPULATION > 2000) and the geometry column with the functions of the DuckDB spatial extension (e.g. ST_Intersects(geometry, ST_MakeEnvelope(4.2, 43.3, 4.9, 43.8))). On a GeoParquet file, DuckDB applies it while reading.
Parameters
Name
Type
Description
Default
relation
duckdb.DuckDBPyRelation
Relation, e.g. from read_parquet or read_geojson.
required
where
str
SQL expression, as in a WHERE clause.
required
Returns
Name
Type
Description
duckdb.DuckDBPyRelation
Raises
Name
Type
Description
ValueError
If the expression is not valid SQL, or refers to an unknown column or function.