Add IS (NOT) DISTINCT FROM operators

None / True / False render as literals.
For SQLite, "IS" is used as SQLite lacks
"IS DISTINCT FROM" but its "IS" operator acts
this way for NULL.

Doctext-author: Mike Bayer <mike_mp@zzzcomputing.com>
Change-Id: I9227b81f7207b42627a0349d14d40b46aa756cce
Pull-request: https://github.com/zzzeek/sqlalchemy/pull/248

1 files changed, 66 insertions, 0 deletions

diff --git a/test/sql/test_operators.py b/test/sql/test_operators.py
index 86286a9a3..5712d8f99 100644
--- a/test/sql/test_operators.py
+++ b/test/sql/test_operators.py
@@ -99,6 +99,18 @@ class DefaultColumnComparatorTest(fixtures.TestBase):
     def test_notequals_true(self):
         self._do_operate_test(operators.ne, True)
 
+    def test_is_distinct_from_true(self):
+        self._do_operate_test(operators.is_distinct_from, True)
+
+    def test_is_distinct_from_false(self):
+        self._do_operate_test(operators.is_distinct_from, False)
+
+    def test_is_distinct_from_null(self):
+        self._do_operate_test(operators.is_distinct_from, None)
+
+    def test_isnot_distinct_from_true(self):
+        self._do_operate_test(operators.isnot_distinct_from, True)
+
     def test_is_true(self):
         self._do_operate_test(operators.is_, True)
 
@@ -1527,6 +1539,60 @@ class OperatorAssociativityTest(fixtures.TestBase, testing.AssertsCompiledSQL):
         self.assert_compile(f / (f / (f - f)), "f / (f / (f - f))")
 
 
+class IsDistinctFromTest(fixtures.TestBase, testing.AssertsCompiledSQL):
+    __dialect__ = 'default'
+
+    table1 = table('mytable',
+                   column('myid', Integer),
+                   )
+
+    def test_is_distinct_from(self):
+        self.assert_compile(self.table1.c.myid.is_distinct_from(1),
+                            "mytable.myid IS DISTINCT FROM :myid_1")
+
+    def test_is_distinct_from_sqlite(self):
+        self.assert_compile(self.table1.c.myid.is_distinct_from(1),
+                            "mytable.myid IS NOT ?",
+                            dialect=sqlite.dialect())
+
+    def test_is_distinct_from_postgresql(self):
+        self.assert_compile(self.table1.c.myid.is_distinct_from(1),
+                            "mytable.myid IS DISTINCT FROM %(myid_1)s",
+                            dialect=postgresql.dialect())
+
+    def test_not_is_distinct_from(self):
+        self.assert_compile(~self.table1.c.myid.is_distinct_from(1),
+                            "mytable.myid IS NOT DISTINCT FROM :myid_1")
+
+    def test_not_is_distinct_from_postgresql(self):
+        self.assert_compile(~self.table1.c.myid.is_distinct_from(1),
+                            "mytable.myid IS NOT DISTINCT FROM %(myid_1)s",
+                            dialect=postgresql.dialect())
+
+    def test_isnot_distinct_from(self):
+        self.assert_compile(self.table1.c.myid.isnot_distinct_from(1),
+                            "mytable.myid IS NOT DISTINCT FROM :myid_1")
+
+    def test_isnot_distinct_from_sqlite(self):
+        self.assert_compile(self.table1.c.myid.isnot_distinct_from(1),
+                            "mytable.myid IS ?",
+                            dialect=sqlite.dialect())
+
+    def test_isnot_distinct_from_postgresql(self):
+        self.assert_compile(self.table1.c.myid.isnot_distinct_from(1),
+                            "mytable.myid IS NOT DISTINCT FROM %(myid_1)s",
+                            dialect=postgresql.dialect())
+
+    def test_not_isnot_distinct_from(self):
+        self.assert_compile(~self.table1.c.myid.isnot_distinct_from(1),
+                            "mytable.myid IS DISTINCT FROM :myid_1")
+
+    def test_not_isnot_distinct_from_postgresql(self):
+        self.assert_compile(~self.table1.c.myid.isnot_distinct_from(1),
+                            "mytable.myid IS DISTINCT FROM %(myid_1)s",
+                            dialect=postgresql.dialect())
+
+
 class InTest(fixtures.TestBase, testing.AssertsCompiledSQL):
     __dialect__ = 'default'