mysql8+mybatis-plus 查询json格式数据

sql 测试json表

CREATE TABLE `testjson` (
  `id` int NOT NULL AUTO_INCREMENT,
  `json_obj` json DEFAULT NULL,
  `json_arr` json DEFAULT NULL,
  `json_str` varchar(100) DEFAULT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci;

INSERT INTO test2.testjson
(id, json_obj, json_arr, json_str)
VALUES(1, '{"age": "1", "sex": "123"}', '[1, 2, 4]', '12');
INSERT INTO test2.testjson
(id, json_obj, json_arr, json_str)
VALUES(2, '{"age": "1", "sex": "123"}', '[1, 2, 4]', '12');
INSERT INTO test2.testjson
(id, json_obj, json_arr, json_str)
VALUES(3, '{"age": "1", "sex": "123"}', '[1, 2, 4]', '12');
INSERT INTO test2.testjson
(id, json_obj, json_arr, json_str)
VALUES(4, '{"age": "1", "sex": "123"}', '[1, 2, 4]', '12');
INSERT INTO test2.testjson
(id, json_obj, json_arr, json_str)
VALUES(5, '{"age": "1", "sex": "123"}', '[1, 2, 4]', '12');

后台springboot 文件pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.6.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>springboot-test</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>demo</name>
    <description>Demo project for Spring Boot</description>
    <properties>
        <java.version>8</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.3.0</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.11</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

application.yml

spring:
    dataSource:
        driver-class-name: com.mysql.cj.jdbc.Driver
        password: root
        url: jdbc:mysql://localhost:3307/test2?characterEncoding=utf8&useSSL=false&serverTimezone=UTC&rewriteBatchedStatements=true
        username: root

实体类User.java

import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableField;
import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableName;
import com.baomidou.mybatisplus.extension.handlers.JacksonTypeHandler;
import lombok.Data;

import java.io.Serializable;

@Data
@TableName(value = "testjson", autoResultMap=true)
public class User implements Serializable {
    private static final long serialVersionUID = 1L;

    @TableId(value = "id", type = IdType.AUTO)
    private Long id;
    @TableField(typeHandler = JacksonTypeHandler.class)
    private JsonObj jsonObj;
    private String jsonArr;
    private String jsonStr;



}

JsonObj,java

@Data
public class JsonObj {
    private String sex;
    private Integer age;
}

UserMapper.java

@Mapper
public interface UserMapper extends BaseMapper<User> {

    User selectById(Long id);
    User selectByLike(String sex);

<?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.springboot.mapper.UserMapper">

    <resultMap id="BaseResultMap" type="com.springboot.entity.User">
        <id column="id" property="id"/>
        <result column="json_obj" property="jsonObj"
        typeHandler="com.baomidou.mybatisplus.extension.handlers.JacksonTypeHandler"/>
        <result column="json_arr" property="jsonArr"/>
        <result column="json_str" property="jsonStr"/>
    </resultMap>

    <select id="selectById" resultMap="BaseResultMap">
        select *from testjson where `id`=#{id}
    </select>

    <select id="selectByLike" resultMap="BaseResultMap">
       select * from testjson where json_obj->'$.sex' like '%'+#{sex}'+%'
    </select>

</mapper>

import com.springboot.mapper.UserMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class TestController {

    @Autowired
    UserMapper userMapper;

   

    @GetMapping("/testJson")
    public String testJson(){
        return "User===:"+userMapper.selectById(1L);
    }
    @GetMapping("/testJsonLike")
    public String testJsonLike(){
        return "User===:"+userMapper.selectByLike("123");
    }
}

备注：常用JSON函数

//插入和更新

JSON_SET和JSON_INSERT区别：set key存在会覆盖value,insert只会插入新的key,value

UPDATE testjson SET json_obj = JSON_SET(json_obj,'$.age','localhost','$.url','www.muscleape.com') WHERE id = 2;

UPDATE testjson SET json_obj = JSON_INSERT(json_obj,'$.url','www.test.com') WHERE id = 3;

//remove元素

UPDATE testjson SET json_obj = json_remove(json_obj, '$.age') WHERE id = 5;

//模糊查询

select * from testjson where json_obj->'$.url' like '%muscleape%'