Handle CHECK constraint integrity in PostgreSQL

PostgreSQL offers CHECK constraints integrity which are currently raised
as generic error. This patch add a filter so they can have their own
exception type.

Change-Id: I7e36ef4385b227d1e62e18277d470047a369a238

1 files changed, 17 insertions, 0 deletions

diff --git a/oslo_db/exception.py b/oslo_db/exception.py
index f950f6a..3b9c3f9 100644
--- a/oslo_db/exception.py
+++ b/oslo_db/exception.py
@@ -87,6 +87,23 @@ class DBDuplicateEntry(DBError):
         super(DBDuplicateEntry, self).__init__(inner_exception)
 
 
+class DBConstraintError(DBError):
+    """Check constraint fails for column error.
+
+    Raised when made an attempt to write to a column a value that does not
+    satisfy a CHECK constraint.
+
+    :kwarg table: the table name for which the check fails
+    :type table: str
+    :kwarg check_name: the table of the check that failed to be satisfied
+    :type check_name: str
+    """
+    def __init__(self, table, check_name, inner_exception=None):
+        self.table = table
+        self.check_name = check_name
+        super(DBConstraintError, self).__init__(inner_exception)
+
+
 class DBReferenceError(DBError):
     """Foreign key violation error.