本文讲述Spring Boot如何通过mybatis-spring-boot-starter集成Mybatis，并且在Mapper中如何映射Model属性和表的字段。
下面给出一个简单的示例。
pom.xml
首先要引入mybatis的依赖
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| <dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>1.1.1</version>
</dependency>
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table_user
数据库建表
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| CREATE TABLE IF NOT EXISTS `tb_user`(
`id` INT(11) NOT NULL,
`name` VARCHAR(100) NOT NULL,
`created_by` VARCHAR(100) NOT NULL,
PRIMARY KEY ( `id` )
)ENGINE=InnoDB DEFAULT CHARSET=utf8;
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User
实体类
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| public class User {
private Integer id;
private String name;
private String createdBy;
}
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UserMapper
Mapper接口中可以通过注解的形式直接写sql，比将sql分离到xml中的方式更方便
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| @Mapper
public interface UserMapper {
@Select("select * from tb_user where id = #{id}")
User selectById(@Param("id") int id);
@Select("select * from tb_user")
List<User> selectAll();
@Insert("insert into tb_user(id, name, created_by) values(#{id}, #{name}, #{createdBy})")
@Results(id = "user",
value = {
@Result(column = "id",property = "id"),
@Result(column = "name",property = "name"),
@Result(column = "created_by",property = "createdBy")
}
)
void insertUser(User user);
@Update("update tb_user set id = #{id}, name = #{name}, created_by = #{createdBy}")
@ResultMap(value = "user")
void updateUser(User user);
@Delete("delete from tb_user where id = #{id}")
void deleteById(@Param("id") int id);
}
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- @Select, @Insert, @Update, @Delete显然就是sql语句的注解了.
- @Param是根据别名取参数的.
- @Results和@Result配合使用, 就可以将实体类属性和表字段进行一一映射.
- @Results的参数id表示这个映射的别名, 可以配合@ResultMap使用.
- @Result的参数column表示表字段名, property表示实体属性名.
- @Options可以在插入时返回主键值, 在这里没什么用. 一般用于在主键id自增的情况下, 插入操作不定义id, 可以在插入数据库表后返回该条插入信息的主键id.
UserService
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| @Service
public class ScriptService {
@Autowired
private UserMapper userMapper;
public User selectById(int id) {
User user = userMapper.selectById(id);
return user;
}
public List<User> selectAll() {
List<User> list = userMapper.selectAll();
return list;
}
public int insertUser(User user) {
userMapper.insertUser(user);
retyrn user.getId();
}
public boolean updateUser(User user) {
int id = user.getId();
user check = userMapper.selectById(id);
if (check == null) {
return false;
}
userMapper.updateUser(user);
return true;
}
public boolean deleteById(int id) {
user check = userMapper.selectById(id);
if (check == null) {
return false;
}
userMapper.deleteById(id);
return true;
}
}
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UserController
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| @Controller
@RequestMapping("/user")
public class UserController {
@Autowired
private UserService userService;
@RequestMapping(value = "/selectById/{id}", method = RequestMethod.GET)
@ResponseBody
public User selectById(@PathVariable("id") int id) {
return userService.selectById(id);
}
@RequestMapping(value = "/selectAll", method = RequestMethod.GET)
@ResponseBody
public List<User> selectAll() {
return userService.selectAll();
}
@RequestMapping(value = "/insertUser", method = RequestMethod.POST)
@ResponseBody
public int insertUser(@RequestBody User user) {
return userService.insertUser(user);
}
@RequestMapping(value = "/updateUser", method = RequestMethod.POST)
@ResponseBody
public boolean updateUser(@RequestBody User user) {
return userService.updateUser(user);
}
@RequestMapping(value = "/deleteById/{id}", method = RequestMethod.POST)
@ResponseBody
public boolean deleteById(@PathVariable("id") int id) {
return userService.deleteById(id);
}
}
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