fix(duckdb): add casts to literals to fix binding errors

Fixes #3629

ibis/backends/duckdb/registry.py

@@ -99,7 +99,7 @@ def _literal(_, expr):
             f"`{type(value).__name__}` isn't yet supported with the duckdb "
             "backend"
         )
-    return sa.literal(value)
+    return sa.cast(sa.literal(value), sqla_type)
 
 
 def _array_column(t, expr):

ibis/backends/tests/test_aggregation.py

@@ -461,3 +461,14 @@ def collect_udf(v):
     )
 
     backend.assert_frame_equal(result, expected, check_like=True)
+
+
+@pytest.mark.notimpl(["datafusion", "pyspark"])
+def test_binds_are_cast(alltypes):
+    expr = alltypes.aggregate(
+        high_line_count=(
+            alltypes.string_col.case().when('1-URGENT', 1).else_(0).end().sum()
+        )
+    )
+
+    expr.execute()

ibis/backends/tests/test_generic.py

@@ -111,7 +111,7 @@ def test_coalesce(backend, con, expr, expected):
         # False
         assert result == decimal.Decimal(str(expected))
     else:
-        assert result == expected
+        assert result == pytest.approx(expected)
 
 
 # TODO(dask) - identicalTo - #2553

ibis/backends/tests/test_temporal.py

@@ -362,7 +362,7 @@ def convert_to_offset(x):
             lambda t, be: t.timestamp_col.date() - ibis.date(date_value),
             lambda t, be: t.timestamp_col.dt.floor('d') - date_value,
             id='date-subtract-date',
-            marks=pytest.mark.notimpl(["duckdb", 'pyspark']),
+            marks=pytest.mark.notimpl(["pyspark"]),
         ),
     ],
 )