目录
一、表结构
二、实体类
三、json处理器
四、配置文件
五、josn数据
1、插入
2、查找
一、表结构
CREATE TABLE "public"."pg_user" (
"id" int8 NOT NULL GENERATED ALWAYS AS IDENTITY (
INCREMENT 1
MINVALUE 1
MAXVALUE 9223372036854775807
START 1
CACHE 1
),
"name" varchar(255) COLLATE "pg_catalog"."default",
"age" int4,
"sex" varchar(255) COLLATE "pg_catalog"."default",
"create_time" timestamp(0),
"create_name" varchar(255) COLLATE "pg_catalog"."default",
"update_time" timestamp(0),
"update_name" varchar(255) COLLATE "pg_catalog"."default",
"is_del" varchar(255) COLLATE "pg_catalog"."default" DEFAULT '0'::character varying,
"liu_xi" json,
CONSTRAINT "pg_user_pkey" PRIMARY KEY ("id")
)
;
ALTER TABLE "public"."pg_user"
OWNER TO "postgres";二、实体类
Entity
package com.chensir.system.domain.entity;
import com.alibaba.fastjson.JSONObject;
import com.baomidou.mybatisplus.annotation.*;
import com.chensir.domain.BaseEntity;
import com.chensir.handler.ObjectJsonHandler;
import lombok.Data;
/**
* @author ChenSir
* @Date 2023/9/11
**/
@Data
@TableName(value = "public.pg_user")
public class PgUser extends BaseEntity {
@TableId(value = "id", type = IdType.AUTO)
private Long id;
private String name;
private Integer age;
private String sex;
private JSONObject liuXi;
@TableLogic
private String isDel;
}
Bo
package com.chensir.system.domain.bo;
import com.alibaba.fastjson.JSONObject;
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.chensir.domain.BaseEntity;
import com.chensir.handler.ObjectJsonHandler;
import lombok.Data;
/**
* @author ChenSir
* @Date 2023/9/11
**/
@Data
public class PgUserBo extends BaseEntity {
private Long id;
private String name;
private Integer age;
private String sex;
private JSONObject liuXi;
}
Vo
package com.chensir.system.domain.vo;
import com.alibaba.fastjson.JSONObject;
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.chensir.handler.ObjectJsonHandler;
import com.fasterxml.jackson.annotation.JsonFormat;
import lombok.Data;
import org.springframework.format.annotation.DateTimeFormat;
import java.time.LocalDateTime;
/**
* @author ChenSir
* @Date 2023/9/11
**/
@Data
public class PgUserVo {
private Long id;
private String name;
private Integer age;
private String sex;
@JsonFormat(timezone = "GMT+8", pattern = "yyyy-MM-dd HH:mm:ss")
@DateTimeFormat(pattern = "yyyy-MM-dd HH:mm:ss")
private LocalDateTime createTime;
private String createName;
@JsonFormat(timezone = "GMT+8", pattern = "yyyy-MM-dd HH:mm:ss")
@DateTimeFormat(pattern = "yyyy-MM-dd HH:mm:ss")
private LocalDateTime updateTime;
private String updateName;
private JSONObject liuXi;
}
三、json处理器
package com.chensir.handler;
import com.alibaba.fastjson.JSONObject;
import org.apache.ibatis.type.BaseTypeHandler;
import org.apache.ibatis.type.JdbcType;
import org.apache.ibatis.type.MappedTypes;
import org.postgresql.util.PGobject;
import java.sql.CallableStatement;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
/**
* pgsql-json处理器
* @author ChenSir
* @Date 2023/9/11
* postgres中json格式的字段，进行转换的自定义转换器，转换为实体类的JSONObject属性
* MappedTypes注解中的类代表此转换器可以自动转换为的java对象
*/
@MappedTypes(JSONObject.class) // 会对使用JSONObject类型的字段进行json映射
public class ObjectJsonHandler extends BaseTypeHandler<JSONObject> {
//引入PGSQL提供的工具类PGobject
private static final PGobject jsonObject = new PGobject();
@Override
public void setNonNullParameter(PreparedStatement ps, int i, JSONObject param, JdbcType jdbcType) throws SQLException {
//转换的操作在这里!!!
jsonObject.setType("json");
jsonObject.setValue(param.toString());
ps.setObject(i, jsonObject);
}
@Override
public JSONObject getNullableResult(ResultSet rs, String columnName) throws SQLException {
String sqlJson = rs.getString(columnName);
if (null != sqlJson) {
return JSONObject.parseObject(sqlJson);
}
return null;
}
//根据列索引，获取可以为空的结果
@Override
public JSONObject getNullableResult(ResultSet rs, int columnIndex) throws SQLException {
String sqlJson = rs.getString(columnIndex);
if (null != sqlJson) {
return JSONObject.parseObject(sqlJson);
}
return null;
}
@Override
public JSONObject getNullableResult(CallableStatement cs, int columnIndex) throws SQLException {
String sqlJson = cs.getString(columnIndex);
if (null != sqlJson) {
return JSONObject.parseObject(sqlJson);
}
return null;
}
} <dependency>
<groupId>org.postgresql</groupId>
<artifactId>postgresql</artifactId>
<version>42.2.14</version>
</dependency>四、配置文件
使用jsonObject需要在Mybatis-plus添加json处理器包路径
type-handlers-package: com.chensir.handler五、josn数据
{
"createtime": "2020-08-06T03:57:08.382Z",
"dataid": "727d2094-f6b3-4eee-a39b-7544c04105fc",
"schemaid": "ec9ebd79-d74d-4e0f-b026-9653006940f2",
"items": {"product": "Toy Train","qty": 2}
}1、插入
INSERT INTO public.pg_user ( liu_xi ) VALUES ( {"createtime":"2020-08-06T03:57:08.382Z","dataid":"727d2094-f6b3-4eee-a39b-7544c04105fc","schemaid":"ec9ebd79-d74d-4e0f-b026-9653006940f2","items": {"product": "Toy Train","qty": 2}} )
2、查找
1、使用select语句查找json数据,与其他基本类型类似
select * from public.pg_user2、查询json中所有dataid作为键
select
liu_xi -> 'dataid' as dataid
from
public.pg_user3、查询json中所有dataid作为文本
select
liu_xi ->> 'dataid' as dataid
from
public.pg_user4、->操作返回json对象，可以链式调用 ->>返回特定节点。
先使用liu_xi-> 'items' 返回对象。然后使用liu_xi -> 'items' ->> 'product' 返回所有产品文本值。
select
liu_xi -> 'items' ->> 'product' as product
from
public.pg_user
order by
productwhere查询略
可参考：
PostgreSQL JSON数据类型_postgis geojson字段类型_梦想画家的博客-CSDN博客
