Fix duplicate CHECK constraints for Boolean/Enum in batch mode

alembic/operations/base.py

@@ -390,6 +390,9 @@ def batch_alter_table(
             :ref:`batch_migrations`
 
         """
+        if naming_convention is None:
+            naming_convention = self.schema_obj.metadata().naming_convention
+
         impl = batch.BatchOperationsImpl(
             self,
             table_name,

alembic/operations/batch.py

@@ -322,7 +322,7 @@ def _adjust_self_columns_for_partial_reordering(self) -> None:
     def _transfer_elements_to_new_table(self) -> None:
         assert self.new_table is None, "Can only create new table once"
 
-        m = MetaData()
+        m = MetaData(naming_convention=self.table.metadata.naming_convention)
         schema = self.table.schema
 
         if self.partial_reordering or self.add_col_ordering:
@@ -537,6 +537,11 @@ def alter_column(
 
             existing.type = type_
 
+            if isinstance(existing.type, SchemaEventTarget):
+                existing.type._create_events = (  # type:ignore[attr-defined]
+                    existing.type.create_constraint  # type:ignore[attr-defined] # noqa
+                ) = False
+
             # we *dont* however set events for the new type, because
             # alter_column is invoked from
             # Operations.implementation_for(alter_column) which already
@@ -618,7 +623,12 @@ def add_column(
         )
         # we copy the column because operations.add_column()
         # gives us a Column that is part of a Table already.
-        self.columns[column.name] = _copy(column, schema=self.table.schema)
+        new_column = _copy(column, schema=self.table.schema)
+        if isinstance(new_column.type, SchemaEventTarget):
+            new_column.type._create_events = (  # type:ignore[attr-defined]
+                new_column.type.create_constraint  # type:ignore[attr-defined] # noqa
+            ) = False
+        self.columns[new_column.name] = new_column
         self.column_transfers[column.name] = {}
 
     def drop_column(

tests/test_batch.py

@@ -413,6 +413,40 @@ def test_rename_col_boolean(self):
             1,
         )
 
+    def test_add_column_boolean_convention(self):
+        m = MetaData(
+            naming_convention={"ck": "ck_%(table_name)s_%(constraint_name)s"}
+        )
+        t = Table(
+            "tname",
+            m,
+            Column("id", Integer, primary_key=True),
+        )
+        impl = ApplyBatchImpl(self.impl, t, (), {}, False)
+        impl.add_column(
+            "tname",
+            Column("flag", Boolean(create_constraint=True, name="ck1")),
+        )
+        ck = CheckConstraint("flag IN (0, 1)", name="ck1")
+        t.append_constraint(ck)
+        impl.add_constraint(ck)
+        new_table = self._assert_impl(
+            impl,
+            ddl_contains="CONSTRAINT ck_tname_ck1 CHECK (flag IN (0, 1))",
+            colnames=["id", "flag"],
+            dialect="sqlite",
+        )
+        eq_(
+            len(
+                [
+                    const
+                    for const in new_table.constraints
+                    if isinstance(const, CheckConstraint)
+                ]
+            ),
+            1,
+        )
+
     def test_change_type_schematype_to_non(self):
         impl = self._boolean_fixture()
         impl.alter_column("tname", "flag", type_=Integer)