BUG: fix isin and selection on selectables

blaze/compute/sql.py

@@ -459,6 +459,16 @@ def compute_up(expr, tbl, predicate, scope=None, **kwargs):
         return select([tbl]).where(predicate)
 
 
+@dispatch(Selection, Selectable, Selectable)
+def compute_up(expr, tbl, predicate, **kwargs):
+    col, = inner_columns(predicate)
+    return reconstruct_select(
+        inner_columns(tbl),
+        tbl,
+        whereclause=unify_wheres((tbl, predicate)),
+    ).where(col)
+
+
 def select(s):
     """ Permissive SQL select
 
@@ -1408,6 +1418,15 @@ def compute_up(expr, data, **kwargs):
     return data.in_(expr._keys)
 
 
+@dispatch(IsIn, Selectable)
+def compute_up(expr, data, **kwargs):
+    assert len(data.columns) == 1, (
+        'only 1 column is allowed in a Select in IsIn'
+    )
+    col, = inner_columns(data)
+    return reconstruct_select((col.in_(expr._keys),), data)
+
+
 @dispatch(Slice, (Select, Selectable, ColumnElement))
 def compute_up(expr, data, **kwargs):
     index = expr.index[0]  # [0] replace_slices returns tuple ((start, stop), )

blaze/compute/tests/test_postgresql_compute.py

@@ -810,3 +810,23 @@ def test_all(sql):
     assert compute(~(s.B == 1).all(), {s: sql}, return_type='core')
     assert compute(~(s.B == 2).all(), {s: sql}, return_type='core')
     assert compute(~(s.B == 3).all(), {s: sql}, return_type='core')
+
+
+def test_isin_selectable(sql):
+    s = symbol('s', discover(sql))
+
+    # wrap the resource in a select
+    assert compute(s.B.isin({1, 3}),
+                   sa.select(sql._resources()[sql].columns),
+                   return_type=list) == [(True,), (False,)]
+
+
+def test_selection_selectable(sql):
+    s = symbol('s', discover(sql))
+
+    # wrap the resource in a select
+    assert (compute(s[s.B.isin({1, 3})],
+                    sa.select(sql._resources()[sql].columns),
+                    return_type=pd.DataFrame) ==
+            pd.DataFrame([['a', 1]],
+                         columns=s.dshape.measure.names)).all().all()

docs/source/whatsnew/0.10.2.txt

@@ -49,6 +49,8 @@ Bug Fixes
   (:issue:`1517`).
 * Fixes issue with string and datetime coercions on Pandas objects
   (:issue:`1519` :issue:`1524`).
+* Fixed a bug with ``isin`` and ``Selection``\s on sql selectables
+  (:issue:`1528`).
 
 Miscellaneous
 ~~~~~~~~~~~~~