Add boolean input param to enable WAL mode

piccolo/engine/sqlite.py

@@ -10,7 +10,7 @@
 from dataclasses import dataclass
 from decimal import Decimal
 from functools import partial, wraps
-from typing import TYPE_CHECKING, Any, Optional, Union
+from typing import TYPE_CHECKING, Any, Literal, Optional, Union
 
 from typing_extensions import Self
 
@@ -590,6 +590,7 @@ def __init__(
         path: str = "piccolo.sqlite",
         log_queries: bool = False,
         log_responses: bool = False,
+        journal_mode: Literal['DELETE', 'TRUNCATE', 'PERSIST', 'MEMORY', 'WAL', 'OFF'] | None = None,
         **connection_kwargs,
     ) -> None:
         """
@@ -602,6 +603,9 @@ def __init__(
         :param log_responses:
             If ``True``, the raw response from each query is printed out.
             Useful for debugging.
+        :param journal_mode:
+            executes the PRAGMA for the given journal mode when returning the db connection.
+            e.g. executes `PRAGMA journal_mode = WAL` if `journal_mode="WAL"`.
         :param connection_kwargs:
             These are passed directly to the database adapter. We recommend
             setting ``timeout`` if you expect your application to process a
@@ -618,6 +622,7 @@ def __init__(
 
         self.log_queries = log_queries
         self.log_responses = log_responses
+        self.journal_mode = journal_mode
         self.connection_kwargs = {
             **default_connection_kwargs,
             **connection_kwargs,
@@ -696,6 +701,10 @@ async def get_connection(self) -> Connection:
         connection = await aiosqlite.connect(**self.connection_kwargs)
         connection.row_factory = dict_factory  # type: ignore
         await connection.execute("PRAGMA foreign_keys = 1")
+
+        if self.journal_mode is not None:
+            await connection.execute(f"PRAGMA journal_mode = {self.journal_mode}")
+
         return connection
 
     ###########################################################################
@@ -724,6 +733,9 @@ async def _run_in_new_connection(
             args = []
         async with aiosqlite.connect(**self.connection_kwargs) as connection:
             await connection.execute("PRAGMA foreign_keys = 1")
+
+            if self.journal_mode is not None:
+                await connection.execute(f"PRAGMA journal_mode = {self.journal_mode}")
 
             connection.row_factory = dict_factory  # type: ignore
             async with connection.execute(query, args) as cursor:
@@ -753,6 +765,9 @@ async def _run_in_existing_connection(
             args = []
         await connection.execute("PRAGMA foreign_keys = 1")
 
+        if self.journal_mode is not None:
+                await connection.execute(f"PRAGMA journal_mode = {self.journal_mode}")
+
         connection.row_factory = dict_factory
         async with connection.execute(query, args) as cursor:
             response = await cursor.fetchall()