check other backends trial1

ormar/models/helpers/sqlalchemy.py

@@ -1,9 +1,7 @@
-import copy
 import logging
 from typing import Dict, List, Optional, TYPE_CHECKING, Tuple, Type, Union
 
 import sqlalchemy
-from sqlalchemy import ForeignKeyConstraint
 
 from ormar import ForeignKey, Integer, ModelDefinitionError  # noqa: I202
 from ormar.fields import BaseField, ManyToManyField
@@ -81,10 +79,12 @@ def create_and_append_m2m_fk(
             model.Meta.tablename + "." + pk_alias,
             ondelete="CASCADE",
             onupdate="CASCADE",
+            name=f"fk_{model_field.through.Meta.tablename}_{model.Meta.tablename}"
+            f"_{field_name}_{pk_alias}",
         ),
     )
     model_field.through.Meta.columns.append(column)
-    model_field.through.Meta.table.append_column(copy.deepcopy(column))
+    model_field.through.Meta.table.append_column(column)
 
 
 def check_pk_column_validity(
@@ -235,18 +235,15 @@ def populate_meta_sqlalchemy_table_if_required(meta: "ModelMeta") -> None:
     if not hasattr(meta, "table") and check_for_null_type_columns_from_forward_refs(
         meta
     ):
-        if meta.tablename == 'albums':
-            meta.constraints.append(ForeignKeyConstraint(['artist'],['artists.id'],
-                                                         ondelete='CASCADE',
-                                                         onupdate='CASCADE'))
+        for constraint in meta.constraints:
+            if isinstance(constraint, sqlalchemy.UniqueConstraint):
+                constraint.name = (
+                    f"uc_{meta.tablename}_"
+                    f'{"_".join([str(col) for col in constraint._pending_colargs])}'
+                )
         table = sqlalchemy.Table(
-            meta.tablename,
-            meta.metadata,
-            *[copy.deepcopy(col) for col in meta.columns],
-            *meta.constraints,
+            meta.tablename, meta.metadata, *meta.columns, *meta.constraints,
         )
-        if meta.tablename == 'albums':
-            pass
         meta.table = table
 
 

ormar/models/metaclass.py

@@ -33,6 +33,7 @@ from ormar.models.helpers import (
     populate_meta_tablename_columns_and_pk,
     register_relation_in_alias_manager,
 )
+from ormar.models.helpers.sqlalchemy import sqlalchemy_columns_from_model_fields
 from ormar.models.quick_access_views import quick_access_set
 from ormar.queryset import QuerySet
 from ormar.relations.alias_manager import AliasManager
@@ -348,20 +349,25 @@ def copy_and_replace_m2m_through_model(
     new_meta: ormar.ModelMeta = type(  # type: ignore
         "Meta", (), dict(through_class.Meta.__dict__),
     )
+    copy_name = through_class.__name__ + attrs.get("__name__", "")
+    copy_through = type(copy_name, (ormar.Model,), {"Meta": new_meta})
     new_meta.tablename += "_" + meta.tablename
     # create new table with copied columns but remove foreign keys
     # they will be populated later in expanding reverse relation
     if hasattr(new_meta, "table"):
         del new_meta.table
-    new_meta.columns = [col for col in new_meta.columns if not col.foreign_keys]
     new_meta.model_fields = {
         name: field
         for name, field in new_meta.model_fields.items()
         if not issubclass(field, ForeignKeyField)
     }
+    if hasattr(new_meta, "column"):
+        del new_meta.columns
+    _, columns = sqlalchemy_columns_from_model_fields(
+        new_meta.model_fields, copy_through
+    )  # type: ignore
+    new_meta.columns = columns
     populate_meta_sqlalchemy_table_if_required(new_meta)
-    copy_name = through_class.__name__ + attrs.get("__name__", "")
-    copy_through = type(copy_name, (ormar.Model,), {"Meta": new_meta})
     copy_field.through = copy_through
 
     parent_fields[field_name] = copy_field