Fixed #30494 -- Disabled __year lookup optimization for indirect values.

The previous heuristics were naively enabling the BETWEEN optimization on
successful cast of the first rhs SQL params to an integer while it was
not appropriate for a lot of database resolved expressions.

Thanks Alexey Chernov for the report.

django/db/models/lookups.py

@@ -508,21 +508,16 @@ class YearExact(YearLookup, Exact):
     lookup_name = 'exact'
 
     def as_sql(self, compiler, connection):
-        # We will need to skip the extract part and instead go
-        # directly with the originating field, that is self.lhs.lhs.
-        lhs_sql, params = self.process_lhs(compiler, connection, self.lhs.lhs)
-        rhs_sql, rhs_params = self.process_rhs(compiler, connection)
-        try:
-            # Check that rhs_params[0] exists (IndexError),
-            # it isn't None (TypeError), and is a number (ValueError)
-            int(rhs_params[0])
-        except (IndexError, TypeError, ValueError):
-            # Can't determine the bounds before executing the query, so skip
-            # optimizations by falling back to a standard exact comparison.
-            return super().as_sql(compiler, connection)
-        bounds = self.year_lookup_bounds(connection, rhs_params[0])
-        params.extend(bounds)
-        return '%s BETWEEN %%s AND %%s' % lhs_sql, params
+        # Avoid the extract operation if the rhs is a direct value to allow
+        # indexes to be used.
+        if self.rhs_is_direct_value():
+            # Skip the extract part by directly using the originating field,
+            # that is self.lhs.lhs.
+            lhs_sql, params = self.process_lhs(compiler, connection, self.lhs.lhs)
+            bounds = self.year_lookup_bounds(connection, self.rhs)
+            params.extend(bounds)
+            return '%s BETWEEN %%s AND %%s' % lhs_sql, params
+        return super().as_sql(compiler, connection)
 
 
 class YearGt(YearComparisonLookup):

tests/db_functions/datetime/test_extract_trunc.py

@@ -4,7 +4,8 @@ import pytz
 
 from django.conf import settings
 from django.db.models import (
-    DateField, DateTimeField, IntegerField, Max, OuterRef, Subquery, TimeField,
+    DateField, DateTimeField, F, IntegerField, Max, OuterRef, Subquery,
+    TimeField,
 )
 from django.db.models.functions import (
     Extract, ExtractDay, ExtractHour, ExtractIsoYear, ExtractMinute,
@@ -108,6 +109,14 @@ class DateFunctionTests(TestCase):
                 query_string = str(qs.query).lower()
                 self.assertEqual(query_string.count(' between '), 1)
                 self.assertEqual(query_string.count('extract'), 0)
+                # an expression rhs cannot use the between optimization.
+                qs = DTModel.objects.annotate(
+                    start_year=ExtractYear('start_datetime'),
+                ).filter(end_datetime__year=F('start_year') + 1)
+                self.assertEqual(qs.count(), 1)
+                query_string = str(qs.query).lower()
+                self.assertEqual(query_string.count(' between '), 0)
+                self.assertEqual(query_string.count('extract'), 3)
 
     def test_extract_year_greaterthan_lookup(self):
         start_datetime = datetime(2015, 6, 15, 14, 10)