Base core models on BaseModel providing sensible defaults.

[plomtask] / plomtask / db.py

diff --git a/plomtask/db.py b/plomtask/db.py
index f53a94c4f085f3664d66f0b0cc38863b217741e1..dfb388b7ec6ed9317f19a788336025a96e4c745e 100644 (file)
--- a/plomtask/db.py
+++ b/plomtask/db.py
@@ -66,3 +66,31 @@ class DatabaseConnection:
     def close(self) -> None:
         """Close DB connection."""
         self.conn.close()
+
+
+class BaseModel:
+    """Template for most of the models we use/derive from the DB."""
+    table_name = ''
+    to_save: list[str] = []
+    id_: None | int | str
+
+    def set_int_id(self, id_: int | None) -> None:
+        """Set id_ if >= 1 or None, else fail."""
+        if (id_ is not None) and id_ < 1:
+            msg = f'illegal {self.__class__.__name__} ID, must be >=1: {id_}'
+            raise HandledException(msg)
+        self.id_ = id_
+
+    def save_core(self, db_conn: DatabaseConnection,
+                  update_with_lastrowid: bool = True) -> None:
+        """Write bare-bones self (sans connected items), ensuring self.id_."""
+        q_marks = ','.join(['?'] * (len(self.to_save) + 1))
+        values = tuple([self.id_] + [getattr(self, key)
+                                     for key in self.to_save])
+        table_name = self.table_name
+        cursor = db_conn.exec(f'REPLACE INTO {table_name} VALUES ({q_marks})',
+                              values)
+        if update_with_lastrowid:
+            self.id_ = cursor.lastrowid
+        cache = getattr(db_conn, f'cached_{table_name}')
+        cache[self.id_] = self