Add support for DATE_TRUNC from INTERVAL to SQLite backend

trytond/CHANGELOG

@@ -1,3 +1,4 @@
+* Add support for DATE_TRUNC from INTERVAL to SQLite backend
 * Add support for EXTRACT from INTERVAL to SQLite backend
 * Add msg_gettext and msg_ngettext to Report context
 * Support plural translation of messages

trytond/trytond/backend/sqlite/database.py

@@ -161,6 +161,8 @@ class SQLiteExtract(Function):
 def date_trunc(field, source):
     if field is None or source is None:
         return None
+    if isinstance(source, (int, float)):  # interval
+        return _date_trunc_interval(field, source)
     for fromisoformat in [
             dt.date.fromisoformat,
             dt.time.fromisoformat,
@@ -199,6 +201,22 @@ def date_trunc(field, source):
         return adapt_timedelta(value)
 
 
+def _date_trunc_interval(field, source):
+    value = dt.timedelta(seconds=source)
+    field = field.lower()
+    for attribute, delta in [
+            ('microseconds', value.microseconds),
+            ('seconds', value.seconds % 60),
+            ('minutes', (value.seconds // 60) % 60),
+            ('hours', (value.seconds // (60 * 60)) % 24),
+            ('days', value.days),
+            ]:
+        if field.startswith(attribute[:-1]):
+            break
+        value -= dt.timedelta(**{attribute: delta})
+    return adapt_timedelta(value)
+
+
 def split_part(text, delimiter, count):
     if text is None:
         return None

trytond/trytond/tests/test_backend.py

@@ -228,6 +228,32 @@ class BackendTestCase(TestCase):
                     value, = cursor.fetchone()
                     self.assertEqual(value, result)
 
+    @with_transaction()
+    def test_function_date_trunc_timedelta(self):
+        "Test DateTrunc function with timedelta"
+        cursor = Transaction().connection.cursor()
+        date = dt.timedelta(
+            days=16, hours=20, minutes=38, seconds=40, microseconds=100)
+        for type_, result in [
+                ('microsecond', dt.timedelta(
+                        days=16, hours=20, minutes=38, seconds=40,
+                        microseconds=100)),
+                ('second', dt.timedelta(
+                        days=16, hours=20, minutes=38, seconds=40)),
+                ('minute', dt.timedelta(days=16, hours=20, minutes=38)),
+                ('hour', dt.timedelta(days=16, hours=20)),
+                ('day', dt.timedelta(days=16)),
+                ('month', dt.timedelta()),
+                ]:
+            for type_ in [type_.lower(), type_.upper()]:
+                with self.subTest(type_=type_):
+                    query = Select([DateTrunc(type_, date).as_('value')])
+                    if backend.name == 'sqlite':
+                        sqlite_apply_types(query, ['INTERVAL'])
+                    cursor.execute(*query)
+                    value, = cursor.fetchone()
+                    self.assertEqual(value, result)
+
     @with_transaction()
     def test_function_date_trunc_null(self):
         "test DateTrunc function with NULL"