From d56b886db07c73764eeaedd49df26fdee869f60e Mon Sep 17 00:00:00 2001
From: Suomm <1474983351@qq.com>
Date: Thu, 8 Jun 2023 12:32:55 +0800
Subject: [PATCH 1/3] =?UTF-8?q?fix:=20=E4=BD=BF=E7=94=A8=20join=20?=
 =?UTF-8?q?=E8=81=94=E8=A1=A8=E6=9F=A5=E8=AF=A2=E4=B8=80=E4=B8=AA=E5=AF=B9?=
 =?UTF-8?q?=E8=B1=A1=EF=BC=8C=E6=95=B0=E6=8D=AE=E4=B8=A2=E5=A4=B1=E3=80=82?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../java/com/mybatisflex/core/BaseMapper.java | 37 +++++++++----------
 .../com/mybatisflex/core/util/SqlUtil.java    | 24 +++++++++++-
 2 files changed, 39 insertions(+), 22 deletions(-)

diff --git a/mybatis-flex-core/src/main/java/com/mybatisflex/core/BaseMapper.java b/mybatis-flex-core/src/main/java/com/mybatisflex/core/BaseMapper.java
index 1faadd63..d2ee7087 100644
--- a/mybatis-flex-core/src/main/java/com/mybatisflex/core/BaseMapper.java
+++ b/mybatis-flex-core/src/main/java/com/mybatisflex/core/BaseMapper.java
@@ -1,17 +1,17 @@
-/**
- * Copyright (c) 2022-2023, Mybatis-Flex (fuhai999@gmail.com).
- * <p>
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- * <p>
- * http://www.apache.org/licenses/LICENSE-2.0
- * <p>
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
+/*
+ *  Copyright (c) 2022-2023, Mybatis-Flex (fuhai999@gmail.com).
+ *  <p>
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *  <p>
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *  <p>
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
  */
 package com.mybatisflex.core;
 
@@ -345,8 +345,7 @@ public interface BaseMapper<T> {
      * @return entity 数据
      */
     default T selectOneByQuery(QueryWrapper queryWrapper) {
-        List<T> entities = selectListByQuery(queryWrapper.limit(1));
-        return (entities == null || entities.isEmpty()) ? null : entities.get(0);
+        return SqlUtil.getSelectOneResult(selectListByQuery(queryWrapper));
     }
 
 
@@ -358,8 +357,7 @@ public interface BaseMapper<T> {
      * @return 数据内容
      */
     default <R> R selectOneByQueryAs(QueryWrapper queryWrapper, Class<R> asType) {
-        List<R> entities = selectListByQueryAs(queryWrapper.limit(1), asType);
-        return (entities == null || entities.isEmpty()) ? null : entities.get(0);
+        return SqlUtil.getSelectOneResult(selectListByQueryAs(queryWrapper, asType));
     }
 
     /**
@@ -495,8 +493,7 @@ public interface BaseMapper<T> {
      * @return 数据量
      */
     default Object selectObjectByQuery(QueryWrapper queryWrapper) {
-        List<Object> objects = selectObjectListByQuery(queryWrapper.limit(1));
-        return objects == null || objects.isEmpty() ? null : objects.get(0);
+        return SqlUtil.getSelectOneResult(selectObjectListByQuery(queryWrapper));
     }
 
 
diff --git a/mybatis-flex-core/src/main/java/com/mybatisflex/core/util/SqlUtil.java b/mybatis-flex-core/src/main/java/com/mybatisflex/core/util/SqlUtil.java
index 68267284..584263ba 100644
--- a/mybatis-flex-core/src/main/java/com/mybatisflex/core/util/SqlUtil.java
+++ b/mybatis-flex-core/src/main/java/com/mybatisflex/core/util/SqlUtil.java
@@ -15,13 +15,18 @@
  */
 package com.mybatisflex.core.util;
 
+import org.apache.ibatis.exceptions.TooManyResultsException;
+import org.apache.ibatis.session.defaults.DefaultSqlSession;
+
 import java.time.LocalDateTime;
 import java.util.Date;
+import java.util.List;
 import java.util.regex.Matcher;
 
 public class SqlUtil {
 
-    private SqlUtil() {}
+    private SqlUtil() {
+    }
 
     public static void keepColumnSafely(String column) {
         if (StringUtil.isBlank(column)) {
@@ -78,7 +83,7 @@ public class SqlUtil {
     }
 
 
-    public static String replaceSqlParams(String sql, Object[] params){
+    public static String replaceSqlParams(String sql, Object[] params) {
         if (params != null && params.length > 0) {
             for (Object value : params) {
                 // null
@@ -108,4 +113,19 @@ public class SqlUtil {
         return sql;
     }
 
+    /**
+     * 搬运加改造 {@link DefaultSqlSession#selectOne(String, Object)}
+     */
+    public static <T> T getSelectOneResult(List<T> list) {
+        if (list == null || list.isEmpty()) {
+            return null;
+        }
+        int size = list.size();
+        if (size == 1) {
+            return list.get(0);
+        }
+        throw new TooManyResultsException(
+                "Expected one result (or null) to be returned by selectOne(), but found: " + size);
+    }
+
 }

From 21ac56facd5f350a9abdec5903ea29b2ecbee851 Mon Sep 17 00:00:00 2001
From: Suomm <1474983351@qq.com>
Date: Thu, 8 Jun 2023 12:33:21 +0800
Subject: [PATCH 2/3] =?UTF-8?q?test:=20=E6=B5=8B=E8=AF=95=E4=BD=BF?=
 =?UTF-8?q?=E7=94=A8=20join=20=E8=81=94=E8=A1=A8=E6=9F=A5=E8=AF=A2?=
 =?UTF-8?q?=E4=B8=80=E4=B8=AA=E5=AF=B9=E8=B1=A1=E3=80=82?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../mybatisflex/test/mapper/UserMapperTest.java    | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/mybatis-flex-test/mybatis-flex-spring-boot-test/src/test/java/com/mybatisflex/test/mapper/UserMapperTest.java b/mybatis-flex-test/mybatis-flex-spring-boot-test/src/test/java/com/mybatisflex/test/mapper/UserMapperTest.java
index 55fd2e34..6b936daa 100644
--- a/mybatis-flex-test/mybatis-flex-spring-boot-test/src/test/java/com/mybatisflex/test/mapper/UserMapperTest.java
+++ b/mybatis-flex-test/mybatis-flex-spring-boot-test/src/test/java/com/mybatisflex/test/mapper/UserMapperTest.java
@@ -18,7 +18,7 @@ package com.mybatisflex.test.mapper;
 
 import com.mybatisflex.core.query.QueryWrapper;
 import com.mybatisflex.test.model.UserInfo;
-import com.mybatisflex.test.model.UserVO1;
+import com.mybatisflex.test.model.UserVO;
 import org.junit.jupiter.api.Test;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.context.SpringBootTest;
@@ -52,10 +52,10 @@ class UserMapperTest {
                 .leftJoin(ROLE).as("r").on(USER_ROLE.ROLE_ID.eq(ROLE.ROLE_ID))
                 .where(USER.USER_ID.eq(3));
         System.out.println(queryWrapper.toSQL());
-//        UserVO userVO = userMapper.selectListByQueryAs(queryWrapper, UserVO.class);
-        UserVO1 userVO = userMapper.selectOneByQueryAs(queryWrapper, UserVO1.class);
-//        UserVO2 userVO = userMapper.selectListByQueryAs(queryWrapper, UserVO2.class);
-//        UserVO3 userVO = userMapper.selectListByQueryAs(queryWrapper, UserVO3.class);
+        UserVO userVO = userMapper.selectOneByQueryAs(queryWrapper, UserVO.class);
+//        UserVO1 userVO = userMapper.selectOneByQueryAs(queryWrapper, UserVO1.class);
+//        UserVO2 userVO = userMapper.selectOneByQueryAs(queryWrapper, UserVO2.class);
+//        UserVO3 userVO = userMapper.selectOneByQueryAs(queryWrapper, UserVO3.class);
         System.err.println(userVO);
     }
 
@@ -68,8 +68,8 @@ class UserMapperTest {
                 .leftJoin(ROLE).as("r").on(USER_ROLE.ROLE_ID.eq(ROLE.ROLE_ID))
                 .where(USER.USER_ID.ge(2));
         System.out.println(queryWrapper.toSQL());
-//        List<UserVO> userVOS = userMapper.selectListByQueryAs(queryWrapper, UserVO.class);
-        List<UserVO1> userVOS = userMapper.selectListByQueryAs(queryWrapper, UserVO1.class);
+        List<UserVO> userVOS = userMapper.selectListByQueryAs(queryWrapper, UserVO.class);
+//        List<UserVO1> userVOS = userMapper.selectListByQueryAs(queryWrapper, UserVO1.class);
 //        List<UserVO2> userVOS = userMapper.selectListByQueryAs(queryWrapper, UserVO2.class);
 //        List<UserVO3> userVOS = userMapper.selectListByQueryAs(queryWrapper, UserVO3.class);
         userVOS.forEach(System.err::println);

From 4bd9ed7ba7ad2781c494d10f8f66ad297b48935f Mon Sep 17 00:00:00 2001
From: Suomm <1474983351@qq.com>
Date: Thu, 8 Jun 2023 12:33:37 +0800
Subject: [PATCH 3/3] =?UTF-8?q?doc:=20=E5=88=A0=E9=99=A4=E6=B3=A8=E6=84=8F?=
 =?UTF-8?q?=E4=BA=8B=E9=A1=B9=E3=80=82?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 docs/zh/base/field-query.md | 13 -------------
 1 file changed, 13 deletions(-)

diff --git a/docs/zh/base/field-query.md b/docs/zh/base/field-query.md
index 980f28e5..e7b1c15d 100644
--- a/docs/zh/base/field-query.md
+++ b/docs/zh/base/field-query.md
@@ -188,16 +188,3 @@ UserVO{userId='1', userName='admin', roleList=[Role{roleId=1, roleKey='admin', r
 UserVO{userId='2', userName='ry', roleList=[Role{roleId=2, roleKey='common', roleName='普通角色'}]}
 UserVO{userId='3', userName='test', roleList=[Role{roleId=1, roleKey='admin', roleName='超级管理员'}, Role{roleId=2, roleKey='common', roleName='普通角色'}]}
 ```
-
-## 特别注意！！！
-
-使用 `join` 联表查询的时候，只能使用 `selectListXxx` 方法查询 List 数据，不能使用 `selectOneXxx` 方法查询单个数据。
-
-```java
-default <R> R selectOneByQueryAs(QueryWrapper queryWrapper, Class<R> asType) {
-    List<R> entities = selectListByQueryAs(queryWrapper.limit(1), asType);
-    return (entities == null || entities.isEmpty()) ? null : entities.get(0);
-}
-```
-
-因为这个 `selectOneXxx` 方法都是调用的对应的 `selectListXxx` 方法，其中添加了 `queryWrapper.limit(1)` 约束，将数据限制在了一条，而联表查询数据有可能是多条的，这样自动映射就会出现数据丢失。
\ No newline at end of file