MyBatis's parameterType input parameter type and resultType return result type

Records : 413

Scenario : The parameterType of MyBatis passes in the parameter type and resultType returns the result type.

Versions : JDK 1.8, Spring Boot 2.6.3, mybatis-3.5.9.

1. The incoming parameter parameterType is Integer

Incoming parameter type parameterType: java.lang.Integer.

Return result type resultType: java.lang.String.

1.1 Mapper interface code

@Repository
public interface CityTypeMapper {
   String getCity01(Integer cityId);
} 

1.2XML code

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.hub.example.mapper.CityTypeMapper">
    <select id="getCity01" parameterType="java.lang.Integer" resultType="java.lang.String">
        select CITY_NAME FROM t_city WHERE CITY_ID=#{cityId}
    </select>   
</mapper>

2. The incoming parameter parameterType is Long

Incoming parameter type parameterType: java.lang.Long.

Return result type resultType: java.lang.String.

2.1 Mapper interface code

@Repository
public interface CityTypeMapper {
   String getCity02(Long cityId);
}

2.2XML code

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.hub.example.mapper.CityTypeMapper">
    <select id="getCity02" parameterType="java.lang.Long" resultType="java.lang.String">
        select CITY_NAME FROM t_city WHERE CITY_ID=#{cityId}
    </select>   
</mapper>

3. The incoming parameter parameterType is Double

Incoming parameter type parameterType: java.lang.Double.

Return result type resultType: java.lang.Double.

3.1 Mapper interface code

@Repository
public interface CityTypeMapper {
   Double getCity03(Double gross);
}

3.2XML code

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.hub.example.mapper.CityTypeMapper">
    <select id="getCity03" parameterType="java.lang.Double" resultType="java.lang.Double">
        select LAND_AREA FROM t_city WHERE GROSS=#{gross}
    </select>   
</mapper>

4. The incoming parameter parameterType is String

Incoming parameter type parameterType: java.lang.String.

Return result type resultType: java.lang.Long.

4.1Mapper interface code

@Repository
public interface CityTypeMapper {
   Long getCity04(String cityName);
}

4.2XML code

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.hub.example.mapper.CityTypeMapper">
    <select id="getCity04" parameterType="java.lang.String" resultType="java.lang.Long">
        select CITY_ID FROM t_city WHERE CITY_NAME=#{cityName}
    </select>   
</mapper>

5. The incoming parameter parameterType is List<Long>

Incoming parameter type parameterType: java.util.ArrayList.

Return result type resultType: java.lang.Long.

5.1Mapper interface code

@Repository
public interface CityTypeMapper {
   long[] getCity05(List<Long> cityIdList);
}

5.2XML code

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.hub.example.mapper.CityTypeMapper">
    <select id="getCity05" parameterType="java.util.ArrayList" resultType="java.lang.Long" >
        select POPULATION FROM t_city WHERE CITY_ID IN
        <foreach collection="list" item="cityId" open="(" separator="," close=")">
            #{cityId}
        </foreach>
    </select>   
</mapper>

6. The incoming parameter parameterType is Long[]

Incoming parameter type parameterType: long[].

Return result type resultType: java.lang.String.

6.1 Mapper interface code

@Repository
public interface CityTypeMapper {
   List<String> getCity06(Long[] cityIdList);
}

6.2XML code

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.hub.example.mapper.CityTypeMapper">
    <select id="getCity06" parameterType="long[]" resultType="java.lang.String">
        select CITY_NAME FROM t_city WHERE CITY_ID IN
        <foreach collection="array" item="cityId" open="(" separator="," close=")">
            #{cityId}
        </foreach>
    </select>   
</mapper>

7. The incoming parameter parameterType is Map<String, Object>

Incoming parameter type parameterType: java.util.Map.

Return result type resultType: com.hub.example.domain.CityPO.

7.1 Mapper interface code

@Repository
public interface CityTypeMapper {
  CityPO getCity07(Map<String, Object> cityMap); 
}

7.2XML code

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.hub.example.mapper.CityTypeMapper">
    <select id="getCity07" parameterType="java.util.Map" resultType="com.hub.example.domain.CityPO">
        select CITY_ID       AS "cityId",
               CITY_NAME     AS "cityName",
               LAND_AREA     AS "landArea",
               POPULATION    AS "population",
               GROSS         AS "gross",
               CITY_DESCRIBE AS "cityDescribe",
               DATA_YEAR     AS "dataYear",
               UPDATE_TIME   AS "updateTime"
        from t_city
        where CITY_ID = #{cityId}
          AND CITY_NAME = #{cityName}
    </select>   
</mapper>

8. The incoming parameter parameterType is CityPO

Incoming parameter type parameterType: com.hub.example.domain.CityPO.

Return result type resultType: java.util.Map.

8.1Mapper interface code

@Repository
public interface CityTypeMapper {
   Map<String, Object> getCity08(CityPO cityPO);   
}

8.2XML code

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.hub.example.mapper.CityTypeMapper">
    <select id="getCity08" parameterType="com.hub.example.domain.CityPO" resultType="java.util.Map">
        select CITY_ID       AS "cityId",
               CITY_NAME     AS "cityName",
               LAND_AREA     AS "landArea",
               POPULATION    AS "population",
               GROSS         AS "gross",
               CITY_DESCRIBE AS "cityDescribe",
               DATA_YEAR     AS "dataYear",
               UPDATE_TIME   AS "updateTime"
        from t_city
        where CITY_ID = #{cityId}
          AND CITY_NAME = #{cityName}
    </select>   
</mapper>

9. The incoming parameter parameterType is Date

Incoming parameter type parameterType: java.util.Date.

Return result type resultType: java.lang.String.

9.1Mapper interface code

@Repository
public interface CityTypeMapper {
  String getCity09(Date date);
}

9.2XML code

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.hub.example.mapper.CityTypeMapper">
    <select id="getCity09" parameterType="java.util.Date" resultType="java.lang.String">
        select CITY_NAME
        FROM t_city
        where UPDATE_TIME = #{date}
    </select>   
</mapper>

10. The incoming parameter parameterType is List<Long>

Incoming parameter type parameterType: java.util.ArrayList.

Return result type resultType: com.hub.example.domain.CityPO.

10.1 Mapper interface code

@Repository
public interface CityTypeMapper {
  List<CityPO> getCity10(List<Long> paraList);   
}

10.2XML code

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.hub.example.mapper.CityTypeMapper">
    <select id="getCity10" parameterType="java.util.ArrayList" resultType="com.hub.example.domain.CityPO">
        select CITY_ID AS "cityId",
        CITY_NAME AS "cityName",
        LAND_AREA AS "landArea",
        POPULATION AS "population",
        GROSS AS "gross",
        CITY_DESCRIBE AS "cityDescribe",
        DATA_YEAR AS "dataYear",
        UPDATE_TIME AS "updateTime"
        from t_city
        WHERE CITY_ID IN
        <foreach collection="list" item="cityId" open="(" separator="," close=")">
            #{cityId}
        </foreach>
    </select>   
</mapper>

11. The incoming parameter parameterType is List<Long>

Incoming parameter type parameterType: java.util.ArrayList.

Return result type resultType: java.util.Map.

11.1 Mapper interface code

@Repository
public interface CityTypeMapper {
   List<Map<String, Object>> getCity11(List<Long> paraList);
}

11.2XML code

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.hub.example.mapper.CityTypeMapper">
    <select id="getCity11" parameterType="java.util.ArrayList" resultType="java.util.Map">
        select CITY_ID AS "cityId",
        CITY_NAME AS "cityName",
        LAND_AREA AS "landArea",
        POPULATION AS "population",
        GROSS AS "gross",
        CITY_DESCRIBE AS "cityDescribe",
        DATA_YEAR AS "dataYear",
        UPDATE_TIME AS "updateTime"
        from t_city
        WHERE CITY_ID IN
        <foreach collection="list" item="cityId" open="(" separator="," close=")">
            #{cityId}
        </foreach>
    </select>   
</mapper>

12. Test code

12.1 Code

@Slf4j
@RestController
@RequestMapping("/hub/example/cityType")
public class CityTypeController {
  @Autowired
  private CityTypeMapper cityTypeMapper;
  @GetMapping("/load01")
  public Object load01() {
    log.info("测试开始...");
    // 1.parameterType: java.lang.Integer; resultType: java.lang.String
    String cityName01 = cityTypeMapper.getCity01(2);
    // 2.parameterType: java.lang.Long; resultType: java.lang.String
    String cityName02 = cityTypeMapper.getCity02(1L);
    // 3.parameterType: java.lang.Double; resultType: java.lang.Double
    double landArea = cityTypeMapper.getCity03(1.81D);
    // 4.parameterType: java.lang.String; resultType: java.lang.Long
    long cityId = cityTypeMapper.getCity04("苏州");
    List<Long> paraList01 = Arrays.asList(1L, 2L);
    // 5.parameterType: java.util.ArrayList; resultType: java.lang.Long
    long[] population = cityTypeMapper.getCity05(paraList01);
    // 6.parameterType: long[]; resultType: java.lang.String
    Long[] paraList02 = new Long[]{1L, 2L};
    List<String> cityNameList = cityTypeMapper.getCity06(paraList02);
    // 7.parameterType: java.util.Map; resultType: com.hub.example.domain.CityPO
    Map<String, Object> map = new HashMap<>();
    map.put("cityId", 3L);
    map.put("cityName", "苏州");
    CityPO cityPO = cityTypeMapper.getCity07(map);
    // 8.parameterType: com.hub.example.domain.CityPO; resultType: java.util.Map
    CityPO cityPO02 = CityPO.builder().cityId(3L).cityName("苏州").build();
    Map<String, Object> map02 = cityTypeMapper.getCity08(cityPO02);
    // 9.parameterType: java.util.Date; resultType: java.lang.String
    Date date = DateUtil.parse("2023-03-10 05:39:16", "yyyy-MM-dd HH:mm:ss");
    String time = cityTypeMapper.getCity09(date);
    // 10.parameterType: java.util.ArrayList; resultType: com.hub.example.domain.CityPO
    List<Long> paraList = Arrays.asList(1L, 2L, 3L);
    List<CityPO> list01 = cityTypeMapper.getCity10(paraList);
    // 11.parameterType: java.util.ArrayList; resultType: java.util.Map
    List<Long> paraList03 = Arrays.asList(1L, 2L, 3L);
    List<Map<String, Object>> list02 = cityTypeMapper.getCity11(paraList03);
    log.info("测试结束...");
return "执行成功";
  }
}

12.2 Test Request

URL01: http://127.0.0.1:18080/hub-example/hub/example/cityType/load01

13. Foundation support

13.1 Entity objects

@Data
@Builder
@NoArgsConstructor
@AllArgsConstructor
public class CityPO implements Serializable {
  private Long cityId;
  private String cityName;
  private Double landArea;
  private Long population;
  private Double gross;
  private String cityDescribe;
  private String dataYear;
  private Date updateTime;
}

13.2 Create table statement

CREATE TABLE t_city (
  CITY_ID BIGINT(16) NOT NULL COMMENT '唯一标识',
  CITY_NAME VARCHAR(64) COLLATE utf8_bin NOT NULL COMMENT '城市名',
  LAND_AREA DOUBLE DEFAULT NULL COMMENT '城市面积',
  POPULATION BIGINT(16) DEFAULT NULL COMMENT '城市人口',
  GROSS DOUBLE DEFAULT NULL COMMENT '生产总值',
  CITY_DESCRIBE VARCHAR(512) COLLATE utf8_bin DEFAULT NULL COMMENT '城市描述',
  DATA_YEAR VARCHAR(16) COLLATE utf8_bin DEFAULT NULL COMMENT '数据年份',
  UPDATE_TIME DATETIME DEFAULT NULL COMMENT '更新时间'
) ENGINE=INNODB DEFAULT CHARSET=utf8 COLLATE=utf8_bin COMMENT='城市信息表';

13.3 Introduce MyBatis dependency

Use the mybatis-spring-boot-starter method to introduce mybatis, corresponding to mybatis-3.5.9 and mybatis-spring-2.0.7 core dependencies.

<dependency>
  <groupId>org.mybatis.spring.boot</groupId>
  <artifactId>mybatis-spring-boot-starter</artifactId>
  <version>2.2.2</version>
</dependency>

Above, thanks.

April 17, 2023