Fixed #33460 -- Used VALUES clause for insert in bulk on SQLite.

SQLite 3.7.11 introduced the ability to use multiple values directly.
SQLite 3.8.8 made multiple values not subject to the
SQLITE_LIMIT_COMPOUND_SELECT (500).

1 files changed, 3 insertions, 4 deletions

diff --git a/django/db/backends/sqlite3/operations.py b/django/db/backends/sqlite3/operations.py
index 34a7251eea..c1a6da4e5d 100644
--- a/django/db/backends/sqlite3/operations.py
+++ b/django/db/backends/sqlite3/operations.py
@@ -337,10 +337,9 @@ class DatabaseOperations(BaseDatabaseOperations):
         return bool(value) if value in (1, 0) else value
 
     def bulk_insert_sql(self, fields, placeholder_rows):
-        return " UNION ALL ".join(
-            "SELECT %s" % ", ".join(row)
-            for row in placeholder_rows
-        )
+        placeholder_rows_sql = (', '.join(row) for row in placeholder_rows)
+        values_sql = ', '.join(f'({sql})' for sql in placeholder_rows_sql)
+        return f'VALUES {values_sql}'
 
     def combine_expression(self, connector, sub_expressions):
         # SQLite doesn't have a ^ operator, so use the user-defined POWER