@Test publicvoidtestInsert(){ User user = new User(); user.setName("张三"); user.setAge(18); user.setEmail("123@qq.com"); int result = userMapper.insert(user); System.out.println(result); } }
@Test publicvoidtestSelect(){ // 按id查询 // ==> Preparing: SELECT id,name,age,email FROM user WHERE id=? User user = userMapper.selectById(1); System.out.println("user = " + user);
// 按id列表查询 // ==> Preparing: SELECT id,name,age,email FROM user WHERE id IN ( ? , ? , ? ) List<User> users = userMapper.selectBatchIds(Arrays.asList(1, 2, 3)); System.out.println("users = " + users);
// 将map集合中不同的查询条件用and连接到一起,按条件查询 // ==> Preparing: SELECT id,name,age,email FROM user WHERE name = ? AND age = ? HashMap<String, Object> map = new HashMap<>(); // 注意此处是表中的列名,不是类中的属性名 map.put("name", "张三"); map.put("age", 18); List<User> userList = userMapper.selectByMap(map); System.out.println("userList = " + userList); }
3、Update
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@Test publicvoidtestUpdate(){ // update时生成的sql自动是动态sql,避免了误操作 // ==> Preparing: UPDATE user SET name=? WHERE id=? User user = new User(); user.setId(1L); user.setName("李四"); int result = userMapper.updateById(user); // 受影响的行数 // result = 1 System.out.println("result = " + result); }
4、Delete
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@Test publicvoidtestDelete(){ // ==> Preparing: DELETE FROM user WHERE id=? int result = userMapper.deleteById(1L); System.out.println("影响的行数:" + result); }
<sqlid="Base_Column_List"> id ,name,age,email </sql>
<selectid="selectAllByName"resultType="com.atguigu.mybatisplus.entity.User"> select <includerefid="Base_Column_List"/> from user where name = #{name} </select>
@Test publicvoidtestSelectAllByName(){ // ==> Preparing: select id,name,age,email from user where name = ? List<User> users = userMapper.selectAllByName("Tom"); users.forEach(System.out::println); }
@Test publicvoidtestListAllByName(){ // ==> Preparing: select id ,name,age,email from user where name = ? List<User> users = userService.listAllByName("Tom"); users.forEach(System.out::println); }