schematype constraints don't use naming convention if it doesnt include "constraint_name"

[Mike Bayer]

this is a little limiting. due to #3067, the constraint convention below will not even be consulted:

from sqlalchemy import *
from sqlalchemy.orm import *
from sqlalchemy.ext.declarative import declarative_base

m1 = MetaData(naming_convention={"ck": "ck_%(table_name)s_%(column_0_name)s"})
Base = declarative_base(metadata=m1)

class A(Base):
    __tablename__ = 'a'
    id = Column(Integer, primary_key=True)
    foob = Column(BOOLEAN)

e = create_engine("mysql://scott:tiger@localhost/test", echo=True)
Base.metadata.drop_all(e)
Base.metadata.create_all(e)

this change needs to be made in order for it to be seen:

diff --git a/lib/sqlalchemy/sql/naming.py b/lib/sqlalchemy/sql/naming.py
index 9e57418..21bf05d 100644
--- a/lib/sqlalchemy/sql/naming.py
+++ b/lib/sqlalchemy/sql/naming.py
@@ -114,8 +114,9 @@ def _constraint_name_for_table(const, table):
     if isinstance(const.name, conv):
         return const.name
     elif convention is not None and (
-        const.name is None or not isinstance(const.name, conv) and
-            "constraint_name" in convention
+        const.name is None or (
+            not isinstance(const.name, conv) or
+            "constraint_name" in convention)
     ):
         return conv(
             convention % ConventionDict(const, table,

there's no reason CheckConstraint can't have a .columns collection so that the columns_0_name convention can be useful.

I dont know that we want to change this for 0.9.

[Mike Bayer]

• The :class:.CheckConstraint construct now supports naming conventions that include the token %(column_0_name)s; the constraint expression is scanned for columns. Additionally, naming conventions for check constraints that don't include the %(constraint_name)s token will now work for :class:.SchemaType- generated constraints, such as those of :class:.Boolean and :class:.Enum; this stopped working in 0.9.7 due to 3067. fixes #3299

→ <<cset 383bb3f70816>>