exc_filters: catch and translate non existent constraint on drop

This patches add a new exception type that is raised when an operation on a non
existing constraint is executed.

Change-Id: Ib55a83b568bdb1c9139af27bd2fbf204508e15e4

1 files changed, 15 insertions, 0 deletions

diff --git a/oslo_db/exception.py b/oslo_db/exception.py
index c5e0fa9..e67ea01 100644
--- a/oslo_db/exception.py
+++ b/oslo_db/exception.py
@@ -127,6 +127,21 @@ class DBReferenceError(DBError):
         super(DBReferenceError, self).__init__(inner_exception)
 
 
+class DBNonExistentConstraint(DBError):
+    """Constraint does not exist.
+
+    :param table: table name
+    :type table: str
+    :param constraint: constraint name
+    :type table: str
+    """
+
+    def __init__(self, table, constraint, inner_exception=None):
+        self.table = table
+        self.constraint = constraint
+        super(DBNonExistentConstraint, self).__init__(inner_exception)
+
+
 class DBDeadlock(DBError):
 
     """Database dead lock error.