diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2fc071e..651b918 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,17 @@
 # ChangeLog
 
+## 0.3
+
+### 0.3.0
+
+- Refactoring migrate logic, and this version is not compatible with previous version.
+- Now there don't need `old_models.py` and it store in database.
+- Upgrade steps:
+  1. Upgrade aerich version.
+  2. Drop aerich model in db and recreate with new struct.
+  3. Delete `migrations/{app}` folder and rerun `aerich init-db`.
+  4. Update model and `aerich migrate` normally.
+
 ## 0.2
 
 ### 0.2.5
diff --git a/README.md b/README.md
index 30de17b..fe58f77 100644
--- a/README.md
+++ b/README.md
@@ -125,7 +125,19 @@ Success upgrade 1_202029051520102929_drop_column.json
 
 Now your db is migrated to latest.
 
-### Downgrade to previous version
+### Downgrade to specified version
+
+```shell
+$ aerich init -h
+
+Usage: aerich downgrade [OPTIONS]
+
+  Downgrade to specified version.
+
+Options:
+  -v, --version INTEGER  Specified version, default to last.  [default: -1]
+  -h, --help             Show this message and exit.
+```
 
 ```shell
 $ aerich downgrade
@@ -133,7 +145,7 @@ $ aerich downgrade
 Success downgrade 1_202029051520102929_drop_column.json
 ```
 
-Now your db rollback to previous version.
+Now your db rollback to specified version.
 
 ### Show history
 
diff --git a/aerich/__init__.py b/aerich/__init__.py
index 01ef120..493f741 100644
--- a/aerich/__init__.py
+++ b/aerich/__init__.py
@@ -1 +1 @@
-__version__ = "0.2.6"
+__version__ = "0.3.0"
diff --git a/aerich/cli.py b/aerich/cli.py
index ddcde9e..a236ea1 100644
--- a/aerich/cli.py
+++ b/aerich/cli.py
@@ -79,10 +79,6 @@ async def cli(ctx: Context, config, app, name):
 @click.pass_context
 @coro
 async def migrate(ctx: Context, name):
-    config = ctx.obj["config"]
-    location = ctx.obj["location"]
-    app = ctx.obj["app"]
-
     ret = await Migrate.migrate(name)
     if not ret:
         return click.secho("No changes detected", fg=Color.yellow)
@@ -90,16 +86,9 @@ async def migrate(ctx: Context, name):
 
 
 @cli.command(help="Upgrade to specified version.")
-@click.option(
-    "--version",
-    default=-1,
-    type=int,
-    show_default=True,
-    help="Specified version, default to latest.",
-)
 @click.pass_context
 @coro
-async def upgrade(ctx: Context, version: int):
+async def upgrade(ctx: Context):
     config = ctx.obj["config"]
     app = ctx.obj["app"]
     location = ctx.obj["location"]
@@ -124,15 +113,18 @@ async def upgrade(ctx: Context, version: int):
                 )
             click.secho(f"Success upgrade {version_file}", fg=Color.green)
             migrated = True
-        if version != -1 and version_file.startswith(str(version)):
-            break
     if not migrated:
         click.secho("No migrate items", fg=Color.yellow)
 
 
 @cli.command(help="Downgrade to specified version.")
 @click.option(
-    "--version", default=-1, type=int, show_default=True, help="Specified version, default to last."
+    "-v",
+    "--version",
+    default=-1,
+    type=int,
+    show_default=True,
+    help="Specified version, default to last.",
 )
 @click.pass_context
 @coro
@@ -142,22 +134,27 @@ async def downgrade(ctx: Context, version: int):
     if version == -1:
         specified_version = await Migrate.get_last_version()
     else:
-        specified_version = await Aerich.filter(app=app, pk=version + 1).first()
+        specified_version = await Aerich.filter(app=app, version__startswith=f"{version}_").first()
     if not specified_version:
         return click.secho("No specified version found", fg=Color.yellow)
-    file = specified_version.version
-    async with in_transaction(get_app_connection_name(config, app)) as conn:
-        file_path = os.path.join(Migrate.migrate_location, file)
-        with open(file_path, "r", encoding="utf-8") as f:
-            content = json.load(f)
-            downgrade_query_list = content.get("downgrade")
-            if not downgrade_query_list:
-                return click.secho("No downgrade item found", fg=Color.yellow)
-            for downgrade_query in downgrade_query_list:
-                await conn.execute_query(downgrade_query)
-            await specified_version.delete()
-        os.unlink(file_path)
-        return click.secho(f"Success downgrade {file}", fg=Color.green)
+    if version == -1:
+        versions = [specified_version]
+    else:
+        versions = await Aerich.filter(app=app, pk__gte=specified_version.pk)
+    for version in versions:
+        file = version.version
+        async with in_transaction(get_app_connection_name(config, app)) as conn:
+            file_path = os.path.join(Migrate.migrate_location, file)
+            with open(file_path, "r", encoding="utf-8") as f:
+                content = json.load(f)
+                downgrade_query_list = content.get("downgrade")
+                if not downgrade_query_list:
+                    return click.secho("No downgrade item found", fg=Color.yellow)
+                for downgrade_query in downgrade_query_list:
+                    await conn.execute_query(downgrade_query)
+                await version.delete()
+            os.unlink(file_path)
+            click.secho(f"Success downgrade {file}", fg=Color.green)
 
 
 @cli.command(help="Show current available heads in migrate location.")
diff --git a/aerich/ddl/sqlite/__init__.py b/aerich/ddl/sqlite/__init__.py
index 3b3eca8..ee66618 100644
--- a/aerich/ddl/sqlite/__init__.py
+++ b/aerich/ddl/sqlite/__init__.py
@@ -13,7 +13,7 @@ class SqliteDDL(BaseDDL):
     DIALECT = SqliteSchemaGenerator.DIALECT
 
     def drop_column(self, model: "Type[Model]", column_name: str):
-        raise NotSupportError("Drop column is not support in SQLite.")
+        raise NotSupportError("Drop column is unsupported in SQLite.")
 
     def modify_column(self, model: "Type[Model]", field_object: Field):
-        raise NotSupportError("Modify column is not support in SQLite.")
+        raise NotSupportError("Modify column is unsupported in SQLite.")
diff --git a/aerich/exceptions.py b/aerich/exceptions.py
index 468865c..a9272ec 100644
--- a/aerich/exceptions.py
+++ b/aerich/exceptions.py
@@ -2,9 +2,3 @@ class NotSupportError(Exception):
     """
     raise when features not support
     """
-
-
-class DuplicationError(Exception):
-    """
-     raise when something duplication
-     """
diff --git a/aerich/migrate.py b/aerich/migrate.py
index c9c409f..a35cd26 100644
--- a/aerich/migrate.py
+++ b/aerich/migrate.py
@@ -115,6 +115,10 @@ class Migrate:
     @classmethod
     async def _generate_diff_sql(cls, name):
         version = await cls.generate_version(name)
+        # delete if same version exists
+        for version_file in cls.get_all_version_files():
+            if version_file.startswith(version.split("_")[0]):
+                os.unlink(os.path.join(cls.migrate_location, version_file))
         content = {
             "upgrade": cls.upgrade_operators,
             "downgrade": cls.downgrade_operators,
diff --git a/pyproject.toml b/pyproject.toml
index 3549bf1..6e19077 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "aerich"
-version = "0.2.6"
+version = "0.3.0"
 description = "A database migrations tool for Tortoise ORM."
 authors = ["long2ice <long2ice@gmail.com>"]
 license = "Apache-2.0"