- Added support for the case of the misbehaving DBAPI that has

pep-249 exception names linked to exception classes of an entirely
different name, preventing SQLAlchemy's own exception wrapping from
wrapping the error appropriately.
The SQLAlchemy dialect in use needs to implement a new
accessor :attr:`.DefaultDialect.dbapi_exception_translation_map`
to support this feature; this is implemented now for the py-postgresql
dialect.
fixes #3421

2 files changed, 40 insertions, 0 deletions

diff --git a/lib/sqlalchemy/testing/suite/__init__.py b/lib/sqlalchemy/testing/suite/__init__.py
index 780aa40aa..9eeffd4cb 100644
--- a/lib/sqlalchemy/testing/suite/__init__.py
+++ b/lib/sqlalchemy/testing/suite/__init__.py
@@ -1,4 +1,5 @@
 
+from sqlalchemy.testing.suite.test_dialect import *
 from sqlalchemy.testing.suite.test_ddl import *
 from sqlalchemy.testing.suite.test_insert import *
 from sqlalchemy.testing.suite.test_sequence import *
diff --git a/lib/sqlalchemy/testing/suite/test_dialect.py b/lib/sqlalchemy/testing/suite/test_dialect.py
new file mode 100644
index 000000000..5ad5694b3
--- /dev/null
+++ b/lib/sqlalchemy/testing/suite/test_dialect.py
@@ -0,0 +1,39 @@
+from .. import fixtures, config
+from sqlalchemy import exc
+from sqlalchemy import Integer, String
+from .. import assert_raises
+from ..schema import Table, Column
+
+
+class ExceptionTest(fixtures.TablesTest):
+    """Test basic exception wrapping.
+
+    DBAPIs vary a lot in exception behavior so to actually anticipate
+    specific exceptions from real round trips, we need to be conservative.
+
+    """
+    run_deletes = 'each'
+
+    __backend__ = True
+
+    @classmethod
+    def define_tables(cls, metadata):
+        Table('manual_pk', metadata,
+              Column('id', Integer, primary_key=True, autoincrement=False),
+              Column('data', String(50))
+              )
+
+    def test_integrity_error(self):
+
+        with config.db.begin() as conn:
+            conn.execute(
+                self.tables.manual_pk.insert(),
+                {'id': 1, 'data': 'd1'}
+            )
+
+            assert_raises(
+                exc.IntegrityError,
+                conn.execute,
+                self.tables.manual_pk.insert(),
+                {'id': 1, 'data': 'd1'}
+            )