fix: config.0013 兼容线上无 unique 约束

config/migrations/0013_tupianpeizhi_drop_type_unique.py

@@ -1,10 +1,47 @@
-from django.db import migrations, models
+from django.db import connection, migrations, models
+
+
+def _table_indexes(table):
+    with connection.cursor() as cursor:
+        cursor.execute(f'SHOW INDEX FROM `{table}`')
+        rows = cursor.fetchall()
+    by_key = {}
+    for row in rows:
+        key_name = row[2]
+        col = row[4]
+        non_unique = row[1]
+        by_key.setdefault(key_name, {'cols': [], 'unique': non_unique == 0})
+        by_key[key_name]['cols'].append(col)
+    return by_key
+
+
+def drop_tupian_unique_add_index(apps, schema_editor):
+    """
+    线上可能从未真正建过 unique(club_id, ImageType)（AlterUniqueTogether 会报 0 constraints）。
+    有则删唯一；索引不存在再补。
+    """
+    table = 'tupianpeizhi'
+    indexes = _table_indexes(table)
+    with connection.cursor() as cursor:
+        for key_name, info in list(indexes.items()):
+            if info['unique'] and info['cols'] == ['club_id', 'ImageType']:
+                cursor.execute(f'ALTER TABLE `{table}` DROP INDEX `{key_name}`')
+        # 刷新后再判断普通索引
+        indexes = _table_indexes(table)
+        if 'tupian_club_type_idx' not in indexes:
+            cursor.execute(
+                f'CREATE INDEX `tupian_club_type_idx` ON `{table}` (`club_id`, `ImageType`)'
+            )
+
+
+def noop_reverse(apps, schema_editor):
+    pass
 
 
 class Migration(migrations.Migration):
     """
     打手规则图(ImageType=1)、关注快手(3) 需支持多图；
-    原先 unique(club_id, ImageType) 会挡掉第二条。默认头像(2)仍由业务层 upsert 保单条。
+    去掉 unique(club_id, ImageType)。默认头像(2)仍由业务层 upsert 保单条。
     """
 
     dependencies = [
@@ -12,15 +49,22 @@ class Migration(migrations.Migration):
     ]
 
     operations = [
-        migrations.AlterUniqueTogether(
-            name='tupianpeizhi',
-            unique_together=set(),
-        ),
-        migrations.AddIndex(
-            model_name='tupianpeizhi',
-            index=models.Index(
-                fields=['club_id', 'ImageType'],
-                name='tupian_club_type_idx',
-            ),
+        migrations.SeparateDatabaseAndState(
+            state_operations=[
+                migrations.AlterUniqueTogether(
+                    name='tupianpeizhi',
+                    unique_together=set(),
+                ),
+                migrations.AddIndex(
+                    model_name='tupianpeizhi',
+                    index=models.Index(
+                        fields=['club_id', 'ImageType'],
+                        name='tupian_club_type_idx',
+                    ),
+                ),
+            ],
+            database_operations=[
+                migrations.RunPython(drop_tupian_unique_add_index, noop_reverse),
+            ],
         ),
     ]