From c983d7905e31e6df8ec42b06e81825c6b4fb37a7 Mon Sep 17 00:00:00 2001
From: 2881099 <2881099@users.noreply.github.com>
Date: Fri, 12 Dec 2025 21:29:55 +0800
Subject: [PATCH] =?UTF-8?q?Updated=20=E5=A4=9A=E8=A1=A8=E6=9F=A5=E8=AF=A2?=
 =?UTF-8?q?=20(markdown)?=
MIME-Version: 1.0
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---
 多表查询.md | 36 +++++++++++++++++-------------------
 1 file changed, 17 insertions(+), 19 deletions(-)

diff --git a/多表查询.md b/多表查询.md
index c7d3af5..7d5f9b2 100644
--- a/多表查询.md
+++ b/多表查询.md
@@ -76,29 +76,27 @@ fsql.Select<Topic, Category, CategoryType>()
 
 > 经验：[一对多，分表只取最后一条记录](https://github.com/dotnetcore/FreeSql/issues/430)
 
-## 3、WithSql
+## 3、WithoutJoin
+
+`WithoutJoin()` 方法提供了一种强大的机制，用于在 FreeSql 的多表查询（例如 `fsql.Select<T1, T2, T3>()`）中，**严格地控制哪些泛型类型对应的表最终会被 JOIN 到生成的 SQL 语句中**。这使得你可以在应用程序层面精确地动态构建查询，替代传统手动拼接 SQL 中对 JOIN 子句的条件控制。
 
 ```csharp
-fsql.Select<Topic, Category, CategoryType>()
-  .WithSql(
-      "select * from Topic where id=@id1",
-      "select * from Category where id=@id2",
-      null, //不设置 CategoryType 对应的 SQL
-      new { id1 = 10, id2 = 11, id3 = 13 }
-  )
-  .LeftJoin((a,b,c) => a.CategoryId == b.Id)
-  .LeftJoin((a,b,c) => b.ParentId == c.Id)
-  .ToList();
-//SELECT ...
-//FROM ( select * from Topic where id=@id1 ) a
-//LEFT JOIN ( select * from Category where id=@id2 ) b ON a.`CategoryId` = b.`Id`
-//LEFT JOIN `CategoryType` c ON b.`ParentId` = c.`Id`
+fsql.Select<Order, Product, User>()
+    .InnerJoin((o, p, u) => o.UserId == u.Id)
+    .LeftJoin((o, p, u) => o.ProductId == p.Id)
+    .WithoutJoin(t2: !includeProductInfo)
+    .ToList((o, p, u) => new OrderDetailDto
+    {
+        OrderId = o.Id,
+        OrderNo = o.OrderNo,
+        Username = u.Username, // User (T3) 始终 JOIN，可直接引用
+        ProductName = includeProductInfo ? p.Name : "N/A"
+    });
+
+// includeProductInfo = true: SQL 将 JOIN Product
+// includeProductInfo = false: SQL 将不 JOIN Product，ProductName 会是 "N/A"
 ```
 
-> 提示：ISelect.ToSql 可与 WithSql 配合使用
-
-> v3.2.666 [WithTempQuery + FromQuery 嵌套查询](%e5%b5%8c%e5%a5%97%e6%9f%a5%e8%af%a2)
-
 ## 4、SQL联表
 ```csharp
 fsql.Select<Topic>()