From f1ec30a7dddb470425a14b11b672d98124aa25a5 Mon Sep 17 00:00:00 2001
From: oyo <oyo@byteawake.com>
Date: Wed, 22 Oct 2025 18:46:01 +0800
Subject: [PATCH] =?UTF-8?q?=E6=9B=B4=E6=96=B0=20knowledge.md?=
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---
 knowledge.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/knowledge.md b/knowledge.md
index fe85a63..b2b32a8 100644
--- a/knowledge.md
+++ b/knowledge.md
@@ -1490,10 +1490,10 @@ class CreateUserBto {    //对应实体user
   - 状态过滤：status != 'CANCELLED'
   - exists子查询：EXISTS(SELECT 1 FROM other_table WHERE ...)
   - count查询：SELECT COUNT(*) WHERE ...; SELECT COUNT(*) > 0 WHERE ...
+  - 一层或多层left join：`SELECT * FROM meeting m LEFT JOIN meeting_agenda ma ON m.id = ma.meeting_id`
 - ❌ 必须自定义查询：
   - GROUP BY聚合：SELECT room_id, COUNT(*) FROM meeting GROUP BY room_id
   - 复杂函数：SELECT DATE_FORMAT(start_time, '%Y-%m') FROM meeting
-  - 1:N关系left join：SELECT * FROM meeting m LEFT JOIN meeting_agenda ma ON m.id = ma.meeting_id（如果是1:N关系）
 - 自定义查询使用读方案能力边界之外的sql实现业务功能
 - 自定义查询无法被TOCO管理，过度使用自定义查询会导致后续代码的维护困难，所以在使用自定义查询之前必须仔细分析是否可以使用读方案，并尽量使用读方案实现
 - 数据访问层使用MyBatis、MyBatisPlus实现