From c124ac63c94f0cb75977c9a9e0a48e0470f9d012 Mon Sep 17 00:00:00 2001
From: admin <570810310@qq.com>
Date: Mon, 22 Feb 2021 16:34:25 +0800
Subject: [PATCH] 1.0.9

---
 .../common/support/AliasQueryWrapper.java     |  6 ++-
 .../github/yulichang/common/support/README.md | 46 ++++++++++++++++++-
 2 files changed, 49 insertions(+), 3 deletions(-)

diff --git a/src/main/java/com/github/yulichang/common/support/AliasQueryWrapper.java b/src/main/java/com/github/yulichang/common/support/AliasQueryWrapper.java
index c4b5eed..eb523b7 100644
--- a/src/main/java/com/github/yulichang/common/support/AliasQueryWrapper.java
+++ b/src/main/java/com/github/yulichang/common/support/AliasQueryWrapper.java
@@ -25,6 +25,10 @@ public class AliasQueryWrapper<T> extends QueryWrapper<T> {
      */
     @Override
     protected String columnToString(String column) {
-        return StringUtils.isBlank(alias) ? column : (alias + StringPool.DOT + column);
+        if (column.lastIndexOf(StringPool.DOT) < 0) {
+            return StringUtils.isBlank(alias) ? column : (alias + StringPool.DOT + column);
+        } else {
+            return column;
+        }
     }
 }
diff --git a/src/main/java/com/github/yulichang/common/support/README.md b/src/main/java/com/github/yulichang/common/support/README.md
index c708b4f..13ac02c 100644
--- a/src/main/java/com/github/yulichang/common/support/README.md
+++ b/src/main/java/com/github/yulichang/common/support/README.md
@@ -2,7 +2,7 @@
 
 [官方自定义sql](https://mp.baomidou.com/guide/wrapper.html#%E4%BD%BF%E7%94%A8-wrapper-%E8%87%AA%E5%AE%9A%E4%B9%89sql)
 
-官方提供的自定义sql不支持表别名和多实体泛型,扩展能力有限,对此就行了优化  
+官方提供的自定义sql不支持表别名和多实体泛型,扩展能力有限,对此就行了优化
 
 原理:  
 AliasQueryWrapper继承QueryWrapper  
@@ -75,8 +75,50 @@ mybatis-plus原生的QueryWrapper也是可以实现别名的,但是没有统一
 
 AliasQueryWrapper.setAlias("u").eq("id", 1);  
 等效与  
-QueryWrapper.eq("u.id", 1);  
+QueryWrapper.eq("u.id", 1);
 
 AliasQueryWrapper别名一次设置全局通用,不需要每个字段都加别名
 
+说明:  
+对于非主表字段查询也是支持的
+
+```java
+class MpJoinTest {
+    @Resource
+    private UserMapper userMapper;
+
+    @Test
+    void test() {
+        UserDTO userDTO = userMapper.userLeftJoin(new AliasQueryWrapper<>()
+                .setAlias("u")
+                .eq("id", "1")
+                .like("sex", "3")
+                .eq("ua.tel", "10086")           //如果查询字段中有点(.)则不会添加别名
+                .like("ua.address", "北京"));
+    }
+}
+```
+对应sql:
+```
+select 
+    u.*,
+    ua.tel 
+from user u 
+    left join user_address ua on u.id = ua.user_id 
+WHERE (
+    u.id = ? 
+    AND u.sex LIKE ? 
+    AND ua.tel = ? 
+    AND ua.address LIKE ?)
+```
+
+注意:如果你喜欢骚操作,请使用原生QueryWrapper  
+举例:
+* .eq("(select sex from user where id = u.id)", "男")
+* .eq("count(u.id)", 1)
+
+不建议在QueryWrapper中使用sql或函数  
+除非你不考虑后续的维护和sql调优
+
+
 QQ群:1022221898
\ No newline at end of file