Fixed #31473 -- Made sql_flush() use RESTART IDENTITY to reset sequences on PostgreSQL.

The sql_flush() positional argument sequences is replaced by the boolean
keyword-only argument reset_sequences. This ensures that the old
function signature can't be used by mistake when upgrading Django. When
the new argument is True, the sequences of the truncated tables will
reset. Using a single boolean value, rather than a list, allows making a
binary yes/no choice as to whether to reset all sequences rather than a
working on a completely different set.

1 files changed, 21 insertions, 20 deletions

diff --git a/django/db/backends/mysql/operations.py b/django/db/backends/mysql/operations.py
index 9d69ba1152..d01e3bef6b 100644
--- a/django/db/backends/mysql/operations.py
+++ b/django/db/backends/mysql/operations.py
@@ -193,29 +193,30 @@ class DatabaseOperations(BaseDatabaseOperations):
         ]
         return 'RETURNING %s' % ', '.join(columns), ()
 
-    def sql_flush(self, style, tables, sequences, allow_cascade=False):
+    def sql_flush(self, style, tables, *, reset_sequences=False, allow_cascade=False):
         if not tables:
             return []
+
         sql = ['SET FOREIGN_KEY_CHECKS = 0;']
-        tables = set(tables)
-        with_sequences = set(s['table'] for s in sequences)
-        # It's faster to TRUNCATE tables that require a sequence reset since
-        # ALTER TABLE AUTO_INCREMENT is slower than TRUNCATE.
-        sql.extend(
-            '%s %s;' % (
-                style.SQL_KEYWORD('TRUNCATE'),
-                style.SQL_FIELD(self.quote_name(table_name)),
-            ) for table_name in tables.intersection(with_sequences)
-        )
-        # Otherwise issue a simple DELETE since it's faster than TRUNCATE
-        # and preserves sequences.
-        sql.extend(
-            '%s %s %s;' % (
-                style.SQL_KEYWORD('DELETE'),
-                style.SQL_KEYWORD('FROM'),
-                style.SQL_FIELD(self.quote_name(table_name)),
-            ) for table_name in tables.difference(with_sequences)
-        )
+        if reset_sequences:
+            # It's faster to TRUNCATE tables that require a sequence reset
+            # since ALTER TABLE AUTO_INCREMENT is slower than TRUNCATE.
+            sql.extend(
+                '%s %s;' % (
+                    style.SQL_KEYWORD('TRUNCATE'),
+                    style.SQL_FIELD(self.quote_name(table_name)),
+                ) for table_name in tables
+            )
+        else:
+            # Otherwise issue a simple DELETE since it's faster than TRUNCATE
+            # and preserves sequences.
+            sql.extend(
+                '%s %s %s;' % (
+                    style.SQL_KEYWORD('DELETE'),
+                    style.SQL_KEYWORD('FROM'),
+                    style.SQL_FIELD(self.quote_name(table_name)),
+                ) for table_name in tables
+            )
         sql.append('SET FOREIGN_KEY_CHECKS = 1;')
         return sql