Updated get_sql_for_connection to read from SQL files

sql/utils.py

@@ -1,3 +1,6 @@
+from pathlib import Path
+
+
 def get_sql_for_connection(schema_editor, direction: str) -> str:
     """
     Returns the vendor and the collection of SQL Statements depending on:
@@ -6,10 +9,17 @@ def get_sql_for_connection(schema_editor, direction: str) -> str:
     2. Direction of Migrations: forward or Backward
     """
     vendor = schema_editor.connection.vendor
+    # Construct Path to SQL
+    file_path = (
+        Path(__file__).parent
+        / "custom_migrations"
+        / f"migrate_{vendor}_{direction}.sql"
+    )
     try:
-        return vendor, CUSTOM_SQL[vendor][direction]
-    except KeyError as error:
+        sql_statement = Path(file_path).read_text()
+    except FileNotFoundError as error:
         # In case it's oracle or some other django supported db that we do not support yet.
         raise RuntimeError(
             f"We currently do not support {vendor}. Please open an issue at https://github.com/dj-stripe/dj-stripe/issues/new?assignees=&labels=discussion&template=feature-or-enhancement-proposal.md&title= if you'd like it supported.",
         ) from error
+    return vendor, sql_statement