start implementing column parity

database.py

@@ -51,6 +51,23 @@ class DBConnector:
     def __exit__(self):
         self._db_stop()
 
+    def _get_cols(self) -> set[str]:
+        """Get the list of columns in the database.
+
+        :return: A list of column names."""
+        query = f"select COLUMN_NAME from information_schema.columns where table_name={DB_TABLE}"
+        rows = {x["COLUMN_NAME"] for x in self._query(query)}
+        return rows
+
+    def _column_parity(self, columns: list[str] | set[str]) -> set[str]:
+        """If the listed columns are not in the database, add them."""
+        cols = set(columns)
+        existing = self._get_cols()
+        needs = cols.difference(existing.intersection(cols))
+        query = f"ALTER TABLE {DB_TABLE} {', '.join([f'ADD COLUMN {c}' for c in needs])}"
+        self._query(query)
+        return self._get_cols()
+
     def _query(self, sql) -> list[dict]:
         """Basic function for running queries.