Hide (almost all) remaining SQL code in DB module.

[plomtask] / plomtask / db.py

diff --git a/plomtask/db.py b/plomtask/db.py
index abd8f6181db946b357902a0ec851f51919f37344..848e750f1a3feccc3d9fb75c192c47a0a4edd4de 100644 (file)
--- a/plomtask/db.py
+++ b/plomtask/db.py
@@ -67,6 +67,42 @@ class DatabaseConnection:
         """Close DB connection."""
         self.conn.close()
 
+    def rewrite_relations(self, table_name: str, key: str, target: int,
+                          rows: list[list[Any]]) -> None:
+        """Rewrite relations in table_name to target, with rows values."""
+        self.delete_where(table_name, key, target)
+        for row in rows:
+            values = tuple([target] + row)
+            q_marks = self.__class__.q_marks_from_values(values)
+            self.exec(f'INSERT INTO {table_name} VALUES {q_marks}', values)
+
+    def row_where(self, table_name: str, key: str,
+                  target: int | str) -> list[Row]:
+        """Return list of Rows at table where key == target."""
+        return list(self.exec(f'SELECT * FROM {table_name} WHERE {key} = ?',
+                              (target,)))
+
+    def column_where(self, table_name: str, column: str, key: str,
+                     target: int | str) -> list[Any]:
+        """Return column of table where key == target."""
+        return [row[0] for row in
+                self.exec(f'SELECT {column} FROM {table_name} '
+                          f'WHERE {key} = ?', (target,))]
+
+    def column_all(self, table_name: str, column: str) -> list[Any]:
+        """Return complete column of table."""
+        return [row[0] for row in
+                self.exec(f'SELECT {column} FROM {table_name}')]
+
+    def delete_where(self, table_name: str, key: str, target: int) -> None:
+        """Delete from table where key == target."""
+        self.exec(f'DELETE FROM {table_name} WHERE {key} = ?', (target,))
+
+    @staticmethod
+    def q_marks_from_values(values: tuple[Any]) -> str:
+        """Return placeholder to insert values into SQL code."""
+        return '(' + ','.join(['?'] * len(values)) + ')'
+
 
 class BaseModel:
     """Template for most of the models we use/derive from the DB."""
@@ -97,8 +133,7 @@ class BaseModel:
             obj = cache[id_]
             from_cache = True
         else:
-            for row in db_conn.exec(f'SELECT * FROM {cls.table_name} '
-                                    'WHERE id = ?', (id_,)):
+            for row in db_conn.row_where(cls.table_name, 'id', id_):
                 obj = cls.from_table_row(db_conn, row)
                 cache[id_] = obj
                 break
@@ -114,11 +149,11 @@ class BaseModel:
     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])
+        q_marks = DatabaseConnection.q_marks_from_values(values)
         table_name = self.table_name
-        cursor = db_conn.exec(f'REPLACE INTO {table_name} VALUES ({q_marks})',
+        cursor = db_conn.exec(f'REPLACE INTO {table_name} VALUES {q_marks}',
                               values)
         if update_with_lastrowid:
             self.id_ = cursor.lastrowid