Check for writable database before starting

CHANGELOG.md

@@ -17,6 +17,7 @@ and this project tries to adhere to [Semantic Versioning](https://semver.org/spe
 ### Fixed
 
 * Create missing PRAGMA values for Loop SQLite database, fixing failing import
+* Check for database existing and able to connect to before doing any writing
 
 ## [0.3.1] - 2021-09-30
 

run.py

@@ -11,6 +11,9 @@ import sys
 
 def migrate(data: NomieImport):
     db = schema.migrate("output.db")
+    if not db:
+        raise ConnectionError
+
     if data.trackers is not None:
 
         habitlist = habits.migrate(db, data.trackers)