accommodate for cloned bindparams w/ maintain_key

Fixed issue where a bound parameter object that was "cloned" would cause a
name conflict in the compiler, if more than one clone of this parameter
were used at the same time in a single statement. This could occur in
particular with things like ORM single table inheritance queries that
indicated the same "discriminator" value multiple times in one query.

Fixes: #6824
Change-Id: Iba7a786fc5a2341ff7d07fc666d24ed790ad4fe8

1 files changed, 16 insertions, 0 deletions

diff --git a/test/sql/test_compiler.py b/test/sql/test_compiler.py
index 40faab486..d270218b2 100644
--- a/test/sql/test_compiler.py
+++ b/test/sql/test_compiler.py
@@ -3589,6 +3589,22 @@ class BindParameterTest(AssertsCompiledSQL, fixtures.TestBase):
             s,
         )
 
+    def test_unique_binds_no_clone_collision(self):
+        """test #6824"""
+        bp = bindparam("foo", unique=True)
+
+        bpc1 = bp._clone(maintain_key=True)
+        bpc2 = bp._clone(maintain_key=True)
+
+        stmt1 = select(bp, bpc1, bpc2)
+
+        # OK, still strange that the double-dedupe logic is still *duping*
+        # the label name, but that's a different issue
+        self.assert_compile(
+            stmt1,
+            "SELECT :foo_1 AS anon_1, :foo_1 AS anon__1, :foo_1 AS anon__1",
+        )
+
     def _test_binds_no_hash_collision(self):
         """test that construct_params doesn't corrupt dict
         due to hash collisions"""