update

嵌套查询.md

@@ -26,11 +26,38 @@ FROM (
 WHERE (a.[rownum] = 1)
 ```
 
-场景2：分组查询后嵌套
+场景2：多表查询嵌套
+
+```c#
+fsql.Select<User1, UserGroup>()
+    .InnerJoin((a, b) => a.GroupId == b.Id)
+    .Where((a, b) => b.GroupName == "group1")
+    .WithTempQuery((a, b) => new
+    {
+        User = a,
+        GroupName = b.GroupName,
+        rownum = SqlExt.RowNumber().Over().PartitionBy(b.GroupName).OrderBy(a.Id).ToValue()
+    })
+    .Where(a => a.rownum == 1)
+    .ToList();
+```
+
+```sql
+SELECT *
+FROM (
+    SELECT a.[Id], a.[Nickname], b.[GroupName], row_number() over( partition by b.[GroupName] order by a.[Id]) [rownum]
+    FROM [User1] a
+    INNER JOIN [UserGroup] b ON a.[GroupId] = b.[Id]
+    WHERE (b.[GroupName] = 'group1')
+ ) a
+WHERE (a.[rownum] = 1)
+```
+
+场景3：分组查询嵌套
 
 待补充..
 
-场景3：嵌套查询 + Join
+场景4：嵌套查询 + Join
 
 待补充..