Default to recorder db for SQL integration (#85436)

Co-authored-by: J. Nick Koston <nick@koston.org>

homeassistant/components/sql/util.py

@@ -0,0 +1,12 @@
+"""Utils for sql."""
+from __future__ import annotations
+
+from homeassistant.components.recorder import get_instance
+from homeassistant.core import HomeAssistant
+
+
+def resolve_db_url(hass: HomeAssistant, db_url: str | None) -> str:
+    """Return the db_url provided if not empty, otherwise return the recorder db_url."""
+    if db_url and not db_url.isspace():
+        return db_url
+    return get_instance(hass).db_url