disctinct then top in select

Author: daimor

sqlalchemy_iris/base.py

@@ -351,11 +351,6 @@ def _get_limit_or_fetch(self, select):
     def get_select_precolumns(self, select, **kw):
 
         text = ""
-        if select._has_row_limiting_clause and self._use_top(select):
-            text += "TOP %s " % self.process(
-                self._get_limit_or_fetch(select), **kw
-            )
-
         if select._distinct or select._distinct_on:
             if select._distinct_on:
                 text += (
@@ -371,6 +366,11 @@ def get_select_precolumns(self, select, **kw):
             else:
                 text += "DISTINCT "
 
+        if select._has_row_limiting_clause and self._use_top(select):
+            text += "TOP %s " % self.process(
+                self._get_limit_or_fetch(select), **kw
+            )
+
         return text
 
     def _use_top(self, select):

sqlalchemy_iris/requirements.py

@@ -65,3 +65,31 @@ def computed_columns_reflect_persisted(self):
         """If persistence information is returned by the reflection of
         computed columns"""
         return exclusions.open()
+
+    @property
+    def two_phase_transactions(self):
+        """Target database must support two-phase transactions."""
+
+        return exclusions.closed()
+
+    @property
+    def binary_comparisons(self):
+        """target database/driver can allow BLOB/BINARY fields to be compared
+        against a bound parameter value.
+        """
+
+        return exclusions.closed()
+
+    @property
+    def binary_literals(self):
+        """target backend supports simple binary literals, e.g. an
+        expression like::
+
+            SELECT CAST('foo' AS BINARY)
+
+        Where ``BINARY`` is the type emitted from :class:`.LargeBinary`,
+        e.g. it could be ``BLOB`` or similar.
+        """
+
+        return exclusions.closed()
+