fix(duckdb): support materializing enum types to pyarrow

ibis/backends/duckdb/__init__.py

@@ -1452,6 +1452,7 @@ def execute(
                     col.to_pylist()
                     if (
                         pat.is_nested(col.type)
+                        or pat.is_dictionary(col.type)
                         or
                         # pyarrow / duckdb type null literals columns as int32?
                         # but calling `to_pylist()` will render it as None

ibis/backends/duckdb/tests/test_client.py

@@ -483,3 +483,23 @@
     assert list(df.columns) == ["value", "id", "date"]
     assert list(schema.names) == ["id", "value", "date"]
     con.create_table(name, df, schema=schema, temp=True)
+
+
+@pytest.mark.parametrize(
+    "converter",
+    [
+        lambda expr: expr.to_pyarrow().to_pylist(),
+        lambda expr: expr.to_pandas().tolist(),
+    ],
+    ids=["pyarrow", "pandas"],
+)
+def test_basic_enum_schema_inference(con, converter):
+    name = gen_name("basic_enum_schema_inference")
+    con.con.execute(
+        f"CREATE TEMP TABLE {name} AS "
+        "SELECT CAST('a' AS ENUM('a', 'b')) e UNION ALL "
+        "SELECT CAST('b' AS ENUM('a', 'b')) e"
+    )
+    t = con.table(name)
+    assert t.e.type() == dt.string
+    assert set(converter(t.e)) == {"a", "b"}

ibis/backends/duckdb/tests/test_datatypes.py

@@ -25,6 +25,7 @@
             ("DATE", dt.date),
             ("DOUBLE", dt.float64),
             ("DECIMAL(10, 3)", dt.Decimal(10, 3)),
+            ("ENUM('a', 'b')", dt.string),
             ("INTEGER", dt.int32),
             ("INTERVAL", dt.Interval("us")),
             ("FLOAT", dt.float32),

ibis/backends/duckdb/tests/test_geospatial.py

@@ -5,7 +5,6 @@
 
 import numpy.testing as npt
 import pandas.testing as tm
-import pyarrow as pa
 import pytest
 from packaging.version import parse as vparse
 from pytest import param
@@ -54,7 +53,9 @@ def test_geospatial_dwithin(assert_sql):
             "geometry_type",
             "geom_type",
             id="geometry_type",
-            marks=pytest.mark.xfail(raises=pa.lib.ArrowTypeError),
+            marks=pytest.mark.xfail(
+                raises=AssertionError, reason="capitalization is different"
+            ),
         ),
     ],
 )