修复了查询subtask时hasChildren字段都为true的Bug

src/main/resources/mapper/TaskMapper.xml

@@ -6,10 +6,10 @@
                task_name,
                task_project_id,
                task_holder_id,
-               s.staff_fullname AS task_holder_name,
+               s.staff_fullname                 AS task_holder_name,
                task_status,
                task_type,
-               task_father_id,
+               t.task_father_id,
                task_created_time,
                task_start_time,
                task_end_time,
@@ -17,11 +17,12 @@
                task_priority,
                task_description,
                attached_info,
-               EXISTS(SELECT task_id FROM task WHERE task_father_id = task.task_id) AS has_children
-        FROM task
-        JOIN (SELECT staff_id, staff_fullname FROM staff) AS s ON task.task_holder_id = s.staff_id
+               judge.task_father_id IS NOT NULL AS has_children
+        FROM task AS t
+                 JOIN (SELECT staff_id, staff_fullname FROM staff) AS s ON t.task_holder_id = s.staff_id
+                 LEFT JOIN (SELECT DISTINCT task_father_id FROM task) AS judge ON t.task_id = judge.task_father_id
         WHERE is_deleted = 0
           AND task_project_id = #{projectId}
-          AND task_father_id = #{fatherId}
+          AND t.task_father_id = #{fatherId}
     </select>
 </mapper>