emulate named args

pylib/anki/dbproxy.py

@@ -3,7 +3,8 @@
 
 from __future__ import annotations
 
-from typing import Any, Iterable, List, Optional, Sequence, Union
+import re
+from typing import Any, Dict, Iterable, List, Optional, Sequence, Tuple, Union
 
 import anki
 
@@ -41,34 +42,35 @@ class DBProxy:
     ################
 
     def _query(
-        self, sql: str, *args: ValueForDB, first_row_only: bool = False
+        self, sql: str, *args: ValueForDB, first_row_only: bool = False, **kwargs
     ) -> List[Row]:
         # mark modified?
         s = sql.strip().lower()
         for stmt in "insert", "update", "delete":
             if s.startswith(stmt):
                 self.mod = True
+        sql, args2 = emulate_named_args(sql, args, kwargs)
         # fetch rows
-        return self._backend.db_query(sql, args, first_row_only)
+        return self._backend.db_query(sql, args2, first_row_only)
 
     # Query shortcuts
     ###################
 
-    def all(self, sql: str, *args: ValueForDB) -> List[Row]:
-        return self._query(sql, *args)
+    def all(self, sql: str, *args: ValueForDB, **kwargs) -> List[Row]:
+        return self._query(sql, *args, **kwargs)
 
-    def list(self, sql: str, *args: ValueForDB) -> List[ValueFromDB]:
-        return [x[0] for x in self._query(sql, *args)]
+    def list(self, sql: str, *args: ValueForDB, **kwargs) -> List[ValueFromDB]:
+        return [x[0] for x in self._query(sql, *args, **kwargs)]
 
-    def first(self, sql: str, *args: ValueForDB) -> Optional[Row]:
-        rows = self._query(sql, *args, first_row_only=True)
+    def first(self, sql: str, *args: ValueForDB, **kwargs) -> Optional[Row]:
+        rows = self._query(sql, *args, first_row_only=True, **kwargs)
         if rows:
             return rows[0]
         else:
             return None
 
-    def scalar(self, sql: str, *args: ValueForDB) -> ValueFromDB:
-        rows = self._query(sql, *args, first_row_only=True)
+    def scalar(self, sql: str, *args: ValueForDB, **kwargs) -> ValueFromDB:
+        rows = self._query(sql, *args, first_row_only=True, **kwargs)
         if rows:
             return rows[0][0]
         else:
@@ -88,3 +90,27 @@ class DBProxy:
         else:
             list_args = list(args)
         self._backend.db_execute_many(sql, list_args)
+
+
+# convert kwargs to list format
+def emulate_named_args(
+    sql: str, args: Tuple, kwargs: Dict[str, Any]
+) -> Tuple[str, Sequence[ValueForDB]]:
+    # nothing to do?
+    if not kwargs:
+        return sql, args
+    print("named arguments in queries will go away in the future:", sql)
+    # map args to numbers
+    arg_num = {}
+    args2 = list(args)
+    for key, val in kwargs.items():
+        args2.append(val)
+        n = len(args2)
+        arg_num[key] = n
+    # update refs
+    def repl(m):
+        arg = m.group(1)
+        return f"?{arg_num[arg]}"
+
+    sql = re.sub(":([a-zA-Z_0-9]+)", repl, sql)
+    return sql, args2

pylib/tests/test_collection.py

@@ -4,6 +4,7 @@ import os
 import tempfile
 
 from anki import Collection as aopen
+from anki.dbproxy import emulate_named_args
 from anki.lang import without_unicode_isolation
 from anki.rsbackend import TR
 from anki.stdmodels import addBasicModel, models
@@ -161,3 +162,13 @@ def test_translate():
     )
     assert no_uni(d.tr(TR.STATISTICS_REVIEWS, reviews=1)) == "1 review"
     assert no_uni(d.tr(TR.STATISTICS_REVIEWS, reviews=2)) == "2 reviews"
+
+
+def test_db_named_args():
+    sql = "select a, 2+:test5 from b where arg =:foo and x = :test5"
+    args = []
+    kwargs = dict(test5=5, foo="blah")
+
+    s, a = emulate_named_args(sql, args, kwargs)
+    assert s == "select a, 2+?1 from b where arg =?2 and x = ?1"
+    assert a == [5, "blah"]