Add rename column support MySQL5

aerich/migrate.py

@@ -4,12 +4,15 @@ import re
 from datetime import datetime
 from importlib import import_module
 from io import StringIO
-from typing import Dict, List, Optional, Tuple, Type
+from typing import Dict, List, Optional, Tuple, Type, Union
 
 import click
+from packaging import version
+from packaging.version import LegacyVersion, Version
 from tortoise import (
     BackwardFKRelation,
     BackwardOneToOneRelation,
+    BaseDBAsyncClient,
     ForeignKeyFieldInstance,
     ManyToManyFieldInstance,
     Model,
@@ -41,6 +44,7 @@ class Migrate:
     app: str
     migrate_location: str
     dialect: str
+    _db_version: Union[LegacyVersion, Version] = None
 
     @classmethod
     def get_old_model_file(cls, app: str, location: str):
@@ -67,6 +71,13 @@ class Migrate:
         except (OSError, FileNotFoundError):
             pass
 
+    @classmethod
+    async def _get_db_version(cls, connection: BaseDBAsyncClient):
+        if cls.dialect == "mysql":
+            sql = "select version() as version"
+            ret = await connection.execute_query(sql)
+            cls._db_version = version.parse(ret[1][0].get("version"))
+
     @classmethod
     async def init_with_old_models(cls, config: dict, app: str, location: str):
         await Tortoise.init(config=config)
@@ -83,7 +94,6 @@ class Migrate:
             await Tortoise.init(config=migrate_config)
 
         connection = get_app_connection(config, app)
-        cls.dialect = connection.schema_generator.DIALECT
         if cls.dialect == "mysql":
             from aerich.ddl.mysql import MysqlDDL
 
@@ -96,6 +106,8 @@ class Migrate:
             from aerich.ddl.postgres import PostgresDDL
 
             cls.ddl = PostgresDDL(connection)
+        cls.dialect = cls.ddl.DIALECT
+        await cls._get_db_version(connection)
 
     @classmethod
     async def _get_last_version_num(cls):
@@ -300,10 +312,16 @@ class Migrate:
                         else:
                             is_rename = diff_key in cls._rename_new
                         if is_rename:
-                            cls._add_operator(
-                                cls._rename_field(new_model, old_field, new_field),
-                                upgrade,
-                            )
+                            if cls.dialect == "mysql" and cls._db_version.major == 5:
+                                cls._add_operator(
+                                    cls._change_field(new_model, old_field, new_field),
+                                    upgrade,
+                                )
+                            else:
+                                cls._add_operator(
+                                    cls._rename_field(new_model, old_field, new_field),
+                                    upgrade,
+                                )
                             break
                 else:
                     cls._add_operator(
@@ -487,6 +505,15 @@ class Migrate:
     def _rename_field(cls, model: Type[Model], old_field: Field, new_field: Field):
         return cls.ddl.rename_column(model, old_field.model_field_name, new_field.model_field_name)
 
+    @classmethod
+    def _change_field(cls, model: Type[Model], old_field: Field, new_field: Field):
+        return cls.ddl.change_column(
+            model,
+            old_field.model_field_name,
+            new_field.model_field_name,
+            new_field.get_for_dialect(cls.dialect, "SQL_TYPE"),
+        )
+
     @classmethod
     def _add_fk(cls, model: Type[Model], field: ForeignKeyFieldInstance):
         """