fix: support mixed collation task backfill

docs/sql/2026-07-30-backfill-school-default-tasks.sql

@@ -12,14 +12,14 @@ CREATE TABLE IF NOT EXISTS school_default_task_initialization (
 ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COMMENT='学校默认实训任务初始化状态';
 
 INSERT INTO task_allocation (id, class_id, school_id, module, disabled_status, sort)
-SELECT UUID(), CONCAT('SCHOOL_DEFAULT:', s.school_id), s.school_id, p.module, p.disabled_status, p.sort
+SELECT UUID(), CONCAT('SCHOOL_DEFAULT:', CONVERT(s.school_id USING BINARY)), s.school_id, p.module, p.disabled_status, p.sort
 FROM school s
-JOIN task_allocation p ON p.class_id = '999999999'
-WHERE s.school_id <> '999999999'
+JOIN task_allocation p ON BINARY p.class_id = BINARY '999999999'
+WHERE BINARY s.school_id <> BINARY '999999999'
   AND NOT EXISTS (
     SELECT 1
     FROM task_allocation existing_task
-    WHERE existing_task.class_id = CONCAT('SCHOOL_DEFAULT:', s.school_id)
+    WHERE BINARY existing_task.class_id = BINARY CONCAT('SCHOOL_DEFAULT:', CONVERT(s.school_id USING BINARY))
   );
 
 INSERT INTO school_default_task_initialization (
@@ -27,14 +27,14 @@ INSERT INTO school_default_task_initialization (
 )
 SELECT s.school_id, 'READY', NULL, 1, NOW(), NOW()
 FROM school s
-WHERE s.school_id <> '999999999'
+WHERE BINARY s.school_id <> BINARY '999999999'
   AND EXISTS (
     SELECT 1
     FROM task_allocation default_task
-    WHERE default_task.class_id = CONCAT('SCHOOL_DEFAULT:', s.school_id)
+    WHERE BINARY default_task.class_id = BINARY CONCAT('SCHOOL_DEFAULT:', CONVERT(s.school_id USING BINARY))
   )
 ON DUPLICATE KEY UPDATE
-  status = IF(status = 'READY', status, 'READY'),
+  status = IF(school_default_task_initialization.status = 'READY', school_default_task_initialization.status, 'READY'),
   update_time = NOW();
 
 COMMIT;