Adding longer database wait time

app/core/database.py

@@ -5,6 +5,7 @@ Works with SQLite (aiosqlite) or Postgres (asyncpg) depending on DATABASE_URL.
 
 from collections.abc import AsyncGenerator
 
+from sqlalchemy import event
 from sqlalchemy.ext.asyncio import (
     AsyncSession,
     async_sessionmaker,
@@ -21,6 +22,19 @@ class Base(DeclarativeBase):
 
 engine = create_async_engine(settings.database_url, echo=settings.debug, future=True)
 
+if engine.sync_engine.dialect.name == "sqlite":
+
+    @event.listens_for(engine.sync_engine, "connect")
+    def _set_sqlite_pragma(dbapi_connection, connection_record) -> None:
+        """WAL mode lets readers/writers avoid blocking each other; busy_timeout
+        makes a connection wait for a lock instead of immediately raising
+        "database is locked" (the pysqlite/aiosqlite default is 0ms).
+        """
+        cursor = dbapi_connection.cursor()
+        cursor.execute("PRAGMA journal_mode=WAL")
+        cursor.execute("PRAGMA busy_timeout=5000")
+        cursor.close()
+
 AsyncSessionLocal = async_sessionmaker(
     engine,
     class_=AsyncSession,