批量操作

docs/01.指南/03.扩展/13.批量操作.md

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+---
+title: 批量操作
+date: 2023-10-24 23:49:00
+permalink: /pages/33c2c2/
+article: false
+---
+# 批量操作
+
+- `3.5.4 +` 版本支持
+
+- 事务需要手动自行控制(默认false)
+
+  注意: autoCommit参数在Spring项目下是无效的,具体见SpringManagedTransactionFactory#newTransaction,在原生mybatis下可用
+
+- 执行返回值为批量处理结果,业务可根据返回值判断是否成功
+
+- saveOrUpdate是个比较有争议的方法,建议批量操作保持为简单的新增或更新操作
+
+  注意: 如果使用批量的sqlSession去执行查询业务的话,就会变得每次都需要flushStatements
+
+- 数据能否写入或更新取决于代码能否正确执行到flushStatements
+
+- 支持Spring与非Spring项目使用
+
+- 执行抛出异常为PersistenceException
+
+# 说明:
+
+## MybatisBatch<?>
+
+- 泛型为具体 **实际数据类型**
+- sqlSessionFactory可通过容器获取,非Spring容器下可在自行初始化Mybatis时将上下文记录起来
+- dataList为实际的批量数据处理 (非空)
+
+## MybatisBatch.Method<?>
+
+- 泛型为 **具体实体**
+- mapperClass为具体的实际Mapper类
+
+## 使用方式
+
+1. 构建MybatisBatch  (将数据与sqlSessionFactory绑定起来)
+2. 构建MybatisBatch.Method (确定执行执行Mapper类方法)
+3. 执行操作 (执行处理操作,将批量参数转换为实际mapper需要的参数)
+
+示例一: 批量插入用户(数据类型为实体)
+
+```java
+List<H2User> userList = List.of(new H2User(2000L, "测试"), new H2User(2001L, "测试"));
+MybatisBatch<H2User> mybatisBatch = new MybatisBatch<>(sqlSessionFactory, userList);
+MybatisBatch.Method<H2User> method = new MybatisBatch.Method<>(H2UserMapper.class);
+mybatisBatch.execute(method.insert());
+
+// 简写
+MybatisBatch.Method<H2User> mapperMethod = new MybatisBatch.Method<>(H2UserMapper.class);
+MybatisBatchUtils.execute(sqlSessionFactory, h2UserList, mapperMethod.insert());
+```
+
+示例二: 批量插入用户(数据类型为非实体)
+
+```java
+List<Long> ids = Arrays.asList(120000L, 120001L);
+MybatisBatch<Long> mybatisBatch = new MybatisBatch<>(sqlSessionFactory, ids);
+MybatisBatch.Method<H2User> method = new MybatisBatch.Method<>(H2UserMapper.class);
+mybatisBatch.execute(method.insert(id -> {
+    // 将id转换为实体
+	H2User h2User = new H2User();
+	h2User.setTestId(id);
+	return h2User;
+}));
+
+// 简写
+MybatisBatch.Method<H2User> mapperMethod = new MybatisBatch.Method<>(H2UserMapper.class);
+MybatisBatchUtils.execute(sqlSessionFactory, ids, mapperMethod.insert(id -> {
+    // 将id转换为实体
+    H2User h2User = new H2User();
+    h2User.setTestId(id);
+    return h2User;
+}));
+```
+
+示例三: 自定义方法插入一
+
+```java
+// mapper方法(方法参数无注解)
+@Insert(
+  "insert into h2user(name,version) values( #{name}, #{version})"
+)
+int myInsertWithoutParam(H2User user1);
+
+// 准备数据集合
+List<H2User> h2UserList = new ArrayList<>();
+for (int i = 0; i < 1000; i++) {
+	h2UserList.add(new H2User("myInsertWithoutParam" + i));
+}
+
+MybatisBatch<H2User> mybatisBatch = new MybatisBatch<>(sqlSessionFactory, h2UserList);
+MybatisBatch.Method<H2User> method = new MybatisBatch.Method<>(H2UserMapper.class);
+mybatisBatch.execute(method.get("myInsertWithoutParam"));
+
+//简写
+MybatisBatch.Method<H2User> mapperMethod = new MybatisBatch.Method<>(H2UserMapper.class);
+MybatisBatchUtils.execute(sqlSessionFactory, h2UserList, mapperMethod.get("myInsertWithoutParam"));
+```
+
+示例四: 自定义方法插入(注解)
+
+```java
+// 方法参数带注解
+@Insert(
+  "insert into h2user(name,version) values( #{user1.name}, #{user1.version})"
+)
+int myInsertWithParam(@Param("user1") H2User user1);
+
+// 准备数据集合
+List<H2User> h2UserList = new ArrayList<>();
+for (int i = 0; i < 1000; i++) {
+	h2UserList.add(new H2User("myInsertWithParam" + i));
+}
+
+MybatisBatch<H2User> mybatisBatch = new MybatisBatch<>(sqlSessionFactory, h2UserList);
+MybatisBatch.Method<H2User> method = new MybatisBatch.Method<>(H2UserMapper.class);
+mybatisBatch.execute(method.get("myInsertWithParam", (user) -> {
+    // 转换成mapper方法参数
+     Map<String, Object> map = new HashMap<>();
+     map.put("user1", user);
+     return map;
+}));
+
+// 简写
+MybatisBatch.Method<H2User> mapperMethod = new MybatisBatch.Method<>(H2UserMapper.class);
+MybatisBatchUtils.execute(sqlSessionFactory, h2UserList, mapperMethod.get("myInsertWithParam", (user) -> {
+     Map<String, Object> map = new HashMap<>();
+     map.put("user1", user);
+    return map;
+}));
+
+```
+
+## 事务处理示例
+
+```java
+@Autowired
+private TransactionTemplate transactionTemplate;
+
+transactionTemplate.execute((TransactionCallback<List<BatchResult>>) status -> {
+    MybatisBatch.Method<H2User> mapperMethod = new MybatisBatch.Method<>(H2UserMapper.class);
+        // 执行批量插入
+    MybatisBatchUtils.execute(sqlSessionFactory, h2UserList, mapperMethod.insert());
+    throw new RuntimeException("出错了");
+});
+```
+