- wip

3 files changed, 71 insertions, 143 deletions

diff --git a/alembic/ddl/base.py b/alembic/ddl/base.py
index dbdc991..f19a9a9 100644
--- a/alembic/ddl/base.py
+++ b/alembic/ddl/base.py
@@ -1,94 +1,20 @@
 import functools
 
 from sqlalchemy.ext.compiler import compiles
-from sqlalchemy.schema import DDLElement, Column, \
-    ForeignKeyConstraint, CheckConstraint
+from sqlalchemy.schema import Column
 from sqlalchemy import Integer
-from sqlalchemy import types as sqltypes
-from sqlalchemy.sql.visitors import traverse
 from .. import util
 
-if util.sqla_09:
-    from sqlalchemy.sql.elements import quoted_name
-
-
-class AlterTable(DDLElement):
-
-    """Represent an ALTER TABLE statement.
-
-    Only the string name and optional schema name of the table
-    is required, not a full Table object.
-
-    """
-
-    def __init__(self, table_name, schema=None):
-        self.table_name = table_name
-        self.schema = schema
-
-
-class RenameTable(AlterTable):
-
-    def __init__(self, old_table_name, new_table_name, schema=None):
-        super(RenameTable, self).__init__(old_table_name, schema=schema)
-        self.new_table_name = new_table_name
-
-
-class AlterColumn(AlterTable):
-
-    def __init__(self, name, column_name, schema=None,
-                 existing_type=None,
-                 existing_nullable=None,
-                 existing_server_default=None):
-        super(AlterColumn, self).__init__(name, schema=schema)
-        self.column_name = column_name
-        self.existing_type = sqltypes.to_instance(existing_type) \
-            if existing_type is not None else None
-        self.existing_nullable = existing_nullable
-        self.existing_server_default = existing_server_default
-
-
-class ColumnNullable(AlterColumn):
-
-    def __init__(self, name, column_name, nullable, **kw):
-        super(ColumnNullable, self).__init__(name, column_name,
-                                             **kw)
-        self.nullable = nullable
-
-
-class ColumnType(AlterColumn):
-
-    def __init__(self, name, column_name, type_, **kw):
-        super(ColumnType, self).__init__(name, column_name,
-                                         **kw)
-        self.type_ = sqltypes.to_instance(type_)
-
-
-class ColumnName(AlterColumn):
-
-    def __init__(self, name, column_name, newname, **kw):
-        super(ColumnName, self).__init__(name, column_name, **kw)
-        self.newname = newname
+# backwards compat
+from ..util.sqla_compat import (  # noqa
+    _table_for_constraint,
+    _columns_for_constraint, _fk_spec, _is_type_bound, _find_columns)
 
 
-class ColumnDefault(AlterColumn):
-
-    def __init__(self, name, column_name, default, **kw):
-        super(ColumnDefault, self).__init__(name, column_name, **kw)
-        self.default = default
-
-
-class AddColumn(AlterTable):
-
-    def __init__(self, name, column, schema=None):
-        super(AddColumn, self).__init__(name, schema=schema)
-        self.column = column
-
-
-class DropColumn(AlterTable):
-
-    def __init__(self, name, column, schema=None):
-        super(DropColumn, self).__init__(name, schema=schema)
-        self.column = column
+from ..operations import RenameTable, AddColumn, DropColumn, \
+    ColumnNullable, ColumnDefault, ColumnType, ColumnName
+if util.sqla_09:
+    from sqlalchemy.sql.elements import quoted_name
 
 
 @compiles(RenameTable)
@@ -154,65 +80,6 @@ def visit_column_default(element, compiler, **kw):
     )
 
 
-def _table_for_constraint(constraint):
-    if isinstance(constraint, ForeignKeyConstraint):
-        return constraint.parent
-    else:
-        return constraint.table
-
-
-def _columns_for_constraint(constraint):
-    if isinstance(constraint, ForeignKeyConstraint):
-        return [fk.parent for fk in constraint.elements]
-    elif isinstance(constraint, CheckConstraint):
-        return _find_columns(constraint.sqltext)
-    else:
-        return list(constraint.columns)
-
-
-def _fk_spec(constraint):
-    if util.sqla_100:
-        source_columns = [
-            constraint.columns[key].name for key in constraint.column_keys]
-    else:
-        source_columns = [
-            element.parent.name for element in constraint.elements]
-
-    source_table = constraint.parent.name
-    source_schema = constraint.parent.schema
-    target_schema = constraint.elements[0].column.table.schema
-    target_table = constraint.elements[0].column.table.name
-    target_columns = [element.column.name for element in constraint.elements]
-
-    return (
-        source_schema, source_table,
-        source_columns, target_schema, target_table, target_columns)
-
-
-def _is_type_bound(constraint):
-    # this deals with SQLAlchemy #3260, don't copy CHECK constraints
-    # that will be generated by the type.
-    if util.sqla_100:
-        # new feature added for #3260
-        return constraint._type_bound
-    else:
-        # old way, look at what we know Boolean/Enum to use
-        return (
-            constraint._create_rule is not None and
-            isinstance(
-                getattr(constraint._create_rule, "target", None),
-                sqltypes.SchemaType)
-        )
-
-
-def _find_columns(clause):
-    """locate Column objects within the given expression."""
-
-    cols = set()
-    traverse(clause, {}, {'column': cols.add})
-    return cols
-
-
 def quote_dotted(name, quote):
     """quote the elements of a dotted name"""
 
diff --git a/alembic/operations/batch.py b/alembic/operations/batch.py
index 9644a33..726df78 100644
--- a/alembic/operations/batch.py
+++ b/alembic/operations/batch.py
@@ -4,7 +4,7 @@ from sqlalchemy import types as sqltypes
 from sqlalchemy import schema as sql_schema
 from sqlalchemy.util import OrderedDict
 from .. import util
-from ..ddl.base import _columns_for_constraint, _is_type_bound
+from ..util.sqla_compat import _columns_for_constraint, _is_type_bound
 
 
 class BatchOperationsImpl(object):
diff --git a/alembic/util/sqla_compat.py b/alembic/util/sqla_compat.py
index 41badd4..d2025aa 100644
--- a/alembic/util/sqla_compat.py
+++ b/alembic/util/sqla_compat.py
@@ -1,5 +1,8 @@
 import re
 from sqlalchemy import __version__
+from sqlalchemy.schema import ForeignKeyConstraint, CheckConstraint
+from sqlalchemy import types as sqltypes
+from sqlalchemy.sql.visitors import traverse
 
 
 def _safe_int(value):
@@ -22,3 +25,61 @@ sqla_099 = _vers >= (0, 9, 9)
 sqla_100 = _vers >= (1, 0, 0)
 sqla_105 = _vers >= (1, 0, 5)
 
+
+def _table_for_constraint(constraint):
+    if isinstance(constraint, ForeignKeyConstraint):
+        return constraint.parent
+    else:
+        return constraint.table
+
+
+def _columns_for_constraint(constraint):
+    if isinstance(constraint, ForeignKeyConstraint):
+        return [fk.parent for fk in constraint.elements]
+    elif isinstance(constraint, CheckConstraint):
+        return _find_columns(constraint.sqltext)
+    else:
+        return list(constraint.columns)
+
+
+def _fk_spec(constraint):
+    if sqla_100:
+        source_columns = [
+            constraint.columns[key].name for key in constraint.column_keys]
+    else:
+        source_columns = [
+            element.parent.name for element in constraint.elements]
+
+    source_table = constraint.parent.name
+    source_schema = constraint.parent.schema
+    target_schema = constraint.elements[0].column.table.schema
+    target_table = constraint.elements[0].column.table.name
+    target_columns = [element.column.name for element in constraint.elements]
+
+    return (
+        source_schema, source_table,
+        source_columns, target_schema, target_table, target_columns)
+
+
+def _is_type_bound(constraint):
+    # this deals with SQLAlchemy #3260, don't copy CHECK constraints
+    # that will be generated by the type.
+    if sqla_100:
+        # new feature added for #3260
+        return constraint._type_bound
+    else:
+        # old way, look at what we know Boolean/Enum to use
+        return (
+            constraint._create_rule is not None and
+            isinstance(
+                getattr(constraint._create_rule, "target", None),
+                sqltypes.SchemaType)
+        )
+
+
+def _find_columns(clause):
+    """locate Column objects within the given expression."""
+
+    cols = set()
+    traverse(clause, {}, {'column': cols.add})
+    return cols