fix creating empty DB when ingest target does not exist

metadex/db.py

@@ -105,15 +105,18 @@ class Db:
     engine: "Engine | None" = None
     is_dirty: bool = False
 
-    def __init__(self, path: Path):
-        self.open(path)
+    def __init__(self, path: Path, *, create_if_missing: bool = True):
+        self.open(path, create_if_missing=create_if_missing)
 
     def __del__(self):
         self.close()
 
-    def open(self, path: Path):
+    def open(self, path: Path, *, create_if_missing: bool = True):
         log.info("Using database: %a", str(path))
 
+        if not create_if_missing and not path.exists():
+            raise FileNotFoundError(f"File does not exist: {path!s}")
+
         if self.engine:
             raise RuntimeError("DB already initialized.")
 

metadex/metadex.py

@@ -324,7 +324,7 @@ def ingest_db_file(
 
     context = _LogContext()
 
-    other_db = db.Db(db_file)
+    other_db = db.Db(db_file, create_if_missing=False)
     with db.transaction() as conn, other_db.transaction(
         force_rollback=True
     ) as other_conn: