diff --git a/python/python/lancedb/util.py b/python/python/lancedb/util.py index dbc52bff6..3cf5460a5 100644 --- a/python/python/lancedb/util.py +++ b/python/python/lancedb/util.py @@ -5,6 +5,7 @@ import binascii import functools import importlib +import math import os import pathlib import warnings @@ -351,6 +352,13 @@ def _(value: int): @value_to_sql.register(float) def _(value: float): + # str() gives "nan" / "inf", which SQL would read as column names. + if math.isnan(value): + return "CAST('NaN' AS DOUBLE)" + if math.isinf(value): + return ( + "CAST('Infinity' AS DOUBLE)" if value > 0 else "CAST('-Infinity' AS DOUBLE)" + ) return str(value) diff --git a/python/python/tests/test_util.py b/python/python/tests/test_util.py index 29cfd7f0b..d9c574eb9 100644 --- a/python/python/tests/test_util.py +++ b/python/python/tests/test_util.py @@ -213,6 +213,35 @@ def test_value_to_sql_numpy_scalars(): assert value_to_sql(np.bool_(False)) == "FALSE" +def test_value_to_sql_nan_and_infinity(tmp_path): + # str(float("nan")) is "nan", which SQL reads as a column named nan, so + # table.update(values={"x": float("nan")}) failed with "No field named nan". + import math + + import numpy as np + + db = lancedb.connect(tmp_path) + table = db.create_table( + "test", + pa.table( + { + "id": [1, 2, 3, 4], + "f64": [1.0, 2.0, 3.0, 4.0], + "f32": pa.array([1.0, 2.0, 3.0, 4.0], pa.float32()), + } + ), + ) + table.update(where="id = 1", values={"f64": float("nan"), "f32": np.nan}) + table.update(where="id = 2", values={"f64": math.inf, "f32": np.float32("inf")}) + table.update(where="id = 3", values={"f64": -math.inf, "f32": -math.inf}) + + rows = {row["id"]: row for row in table.to_arrow().to_pylist()} + assert math.isnan(rows[1]["f64"]) and math.isnan(rows[1]["f32"]) + assert rows[2]["f64"] == math.inf and rows[2]["f32"] == math.inf + assert rows[3]["f64"] == -math.inf and rows[3]["f32"] == -math.inf + assert rows[4]["f64"] == 4.0 and rows[4]["f32"] == 4.0 + + def test_append_vector_columns(): registry = EmbeddingFunctionRegistry.get_instance() registry.register("test")(MockTextEmbeddingFunction)