refactor: inherit IntField to reduce duplicated code (#1628)

tortoise/fields/data.py

@@ -101,7 +101,7 @@ class _db_oracle:
         GENERATED_SQL = "INT GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY NOT NULL"
 
 
-class BigIntField(Field[int], int):
+class BigIntField(IntField):
     """
     Big integer field. (64-bit signed)
 
@@ -110,12 +110,6 @@ class BigIntField(Field[int], int):
     """
 
     SQL_TYPE = "BIGINT"
-    allows_generated = True
-
-    def __init__(self, primary_key: Optional[bool] = None, **kwargs: Any) -> None:
-        if primary_key or kwargs.get("pk"):
-            kwargs["generated"] = bool(kwargs.get("generated", True))
-        super().__init__(primary_key=primary_key, **kwargs)
 
     @property
     def constraints(self) -> dict:
@@ -127,9 +121,6 @@ def constraints(self) -> dict:
     class _db_postgres:
         GENERATED_SQL = "BIGSERIAL NOT NULL PRIMARY KEY"
 
-    class _db_sqlite:
-        GENERATED_SQL = "INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL"
-
     class _db_mysql:
         GENERATED_SQL = "BIGINT NOT NULL PRIMARY KEY AUTO_INCREMENT"
 
@@ -141,7 +132,7 @@ class _db_oracle:
         GENERATED_SQL = "INT GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY NOT NULL"
 
 
-class SmallIntField(Field[int], int):
+class SmallIntField(IntField):
     """
     Small integer field. (16-bit signed)
 
@@ -150,12 +141,6 @@ class SmallIntField(Field[int], int):
     """
 
     SQL_TYPE = "SMALLINT"
-    allows_generated = True
-
-    def __init__(self, primary_key: Optional[bool] = None, **kwargs: Any) -> None:
-        if primary_key or kwargs.get("pk"):
-            kwargs["generated"] = bool(kwargs.get("generated", True))
-        super().__init__(primary_key=primary_key, **kwargs)
 
     @property
     def constraints(self) -> dict:
@@ -167,9 +152,6 @@ def constraints(self) -> dict:
     class _db_postgres:
         GENERATED_SQL = "SMALLSERIAL NOT NULL PRIMARY KEY"
 
-    class _db_sqlite:
-        GENERATED_SQL = "INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL"
-
     class _db_mysql:
         GENERATED_SQL = "SMALLINT NOT NULL PRIMARY KEY AUTO_INCREMENT"