MyBatis 处理 MySQL5.7 的json字段数据
网上查询后，了解到 MySQL 5.7 以后版本居然加入了 json 字段，这下有搞头了！
赶紧查了一下我的 MySQL 版本：是大于 V5.7 的，在支持范围内
等等，我怎么在Navicat 上怎么找不到 json 字段类型 ，又是一番查找，原来 Navicat 版本太低不支持。。。所以我又升级到 Navicat Premium 12 版本了，这下 json 字段出来了，那这个 json 字段类型对应的 Java bean 属性又是什么呢？MyBatis 怎么写 sql 呢？
额，MyBatis 还不支持直接处理MySQL json字段。。。只能通过自定义 TypeHandler 来转化，行吧，那就写呗。不过之前要看看List 、Object 这两个是有区别的，所以我分别写了 ObjectJsonTypeHandler.java、ObjectListJsonTypeHandler.java
（ 选择 com.alibaba.fastjson 工具类下的）
然后就是两个自定义 TypeHandler 了：首先是ObjectJsonTypeHandler.java
/*
* Copyright 2019 Wicrenet, Inc. All rights reserved.
*/
package com.xy.pay.main.dao.handler;
/*
* Copyright 2019 Wicrenet, Inc. All rights reserved.
*/
import com.alibaba.fastjson.JSON;
import org.apache.ibatis.type.BaseTypeHandler;
import org.apache.ibatis.type.JdbcType;
import java.sql.CallableStatement;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
/**
* @author YJX
* @date 2019-08-23 11:30
* 普通对象存取数据库数据库字段为json类型
**/
public class ObjectJsonTypeHandler<T extends Object> extends BaseTypeHandler<T> {
private Class<T> clazz;
public ObjectJsonTypeHandler(Class<T> clazz) {
if (clazz == null) {
throw new IllegalArgumentException("Type argument cannot be null");
}
this.clazz = clazz;
}
@Override
public void setNonNullParameter(PreparedStatement ps, int i, T parameter, JdbcType jdbcType) throws SQLException {
ps.setString(i, JSON.toJSONString(parameter));
}
@Override
public T getNullableResult(ResultSet rs, String columnName) throws SQLException {
return this.toObject(rs.getObject(columnName), clazz);
}
@Override
public T getNullableResult(ResultSet rs, int columnIndex) throws SQLException {
return this.toObject(rs.getObject(columnIndex), clazz);
}
@Override
public T getNullableResult(CallableStatement cs, int columnIndex) throws SQLException {
return this.toObject(cs.getObject(columnIndex), clazz);
}
private T toObject(Object content, Class<T> clazz) {
if (content == null) {
return null;
}
return JSON.parseObject(content.toString(), clazz);
}
}
ObjectListJsonTypeHandler.java 如下
/*
* Copyright 2019 Wicrenet, Inc. All rights reserved.
*/
package com.xy.pay.main.dao.handler;
/*
* Copyright 2019 Wicrenet, Inc. All rights reserved.
*/
import com.alibaba.fastjson.JSON;
import org.apache.ibatis.type.BaseTypeHandler;
import org.apache.ibatis.type.JdbcType;
import java.sql.CallableStatement;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.List;
/**
* @author YJX
* @date 2019-08-23 11:30
* 数组对象存取数据库数据库字段为json类型
**/
public class ObjectListJsonTypeHandler<T> extends BaseTypeHandler<List<T>> {
private Class<T> clazz;
public ObjectListJsonTypeHandler(Class<T> clazz) {
if (clazz == null) {
throw new IllegalArgumentException("Type argument cannot be null");
}
this.clazz = clazz;
}
@Override
public void setNonNullParameter(PreparedStatement ps, int i, List<T> parameter, JdbcType jdbcType) throws SQLException {
ps.setString(i, JSON.toJSONString(parameter));
}
@Override
public List<T> getNullableResult(ResultSet rs, String columnName) throws SQLException {
return this.toObject(rs.getObject(columnName), clazz);
}
@Override
public List<T> getNullableResult(ResultSet rs, int columnIndex) throws SQLException {
return this.toObject(rs.getObject(columnIndex), clazz);
}
@Override
public List<T> getNullableResult(CallableStatement cs, int columnIndex) throws SQLException {
return this.toObject(cs.getObject(columnIndex), clazz);
}
private List<T> toObject(Object content, Class<T> clazz) {
if (content == null) {
return null;
}
return JSON.parseArray(content.toString(), clazz);
}
}
mybatis中使用 ObjectJsonTypeHandler.java和ObjectListJsonTypeHandler.java使用是不一样的呢
object和普通枚举一样使用
存list取的时候需要指定转换的typeJava对象 , 如下图
<mapper namespace="com.xy.pay.main.dao.SysUserDao">
<resultMap id="mapper" type="com.xy.pay.main.dao.model.SysUser">
<id column="id" property="id"/>
<result column="hierarchy" property="hierarchy"/>
<result column="name" property="name"/>
<result column="password" property="password"/>
<result column="enabled" property="enabled"/>
<result column="phone" property="phone"/>
<result column="uservos" property="uservos" javaType="com.xy.pay.main.controller.model.SysUserVo"
typeHandler="com.xy.pay.main.dao.handler.ObjectListJsonTypeHandler"/>
<association property="parent" columnPrefix="parent_" resultMap="mapper"/>
resultMap>
<sql id="baseWhere">
<trim prefixOverrides="and">
<if test="id_eq != null">
and `id` = #{id_eq}
if>
<if test="id_in != null">
and id in
<foreach collection="id_in" open="(" item="id_in_item" separator="," close=")">
#{id_in_item}
foreach>
if>
<if test="parentId_eq != null">
and `parent_id` = #{parentId_eq}
if>
<if test="hierarchy_eq != null">
and `hierarchy` = #{hierarchy_eq}
if>
<if test="hierarchy_lk != null">
and `hierarchy` LIKE #{hierarchy_lk}
if>
<if test="name_eq != null">
and `name` = #{name_eq}
if>
<if test="password_eq != null">
and `password` = #{password_eq}
if>
<if test="enabled_eq != null">
and `enabled` = #{enabled_eq}
if>
<if test="phone_eq != null">
and `phone` = #{phone_eq}
if>
<if test="userves_name_eq != null">
and JSON_CONTAINS( uservos -> '$[*].name',CONCAT('"',#{userves_name_eq},'"'), '$' )
if>
trim>
sql>
<sql id="where">
<if test="default_where != null and default_where">
<where>
<include refid="baseWhere"/>
where>
if>
<if test="default_where == null or !default_where">
WHERE
<include refid="baseWhere"/>
if>
sql>
<sql id="columns">
<if test="use_dynamic_column != null and use_dynamic_column">
<trim suffixOverrides=",">
<if test="field_id != null">
id,
if>
<if test="field_parent != null">
parent_id,
if>
<if test="field_hierarchy != null">
hierarchy,
if>
<if test="field_name != null">
name,
if>
<if test="field_password != null">
password,
if>
<if test="field_enabled != null">
enabled,
if>
<if test="field_phone != null">
phone,
if>
<if test="field_uservos != null">
uservos,
if>
trim>
if>
<if test="use_dynamic_column == null or !use_dynamic_column">
id
,parent_id
,hierarchy
,name
,password
,enabled
,phone
,uservos
if>
sql>
<sql id="orderBy">
<if test="order_by_map != null and !order_by_map.isEmpty()">
ORDER BY
<foreach collection="order_by_map" index="key" item="val" separator=",">
<if test="key == 'id'">
id ${val}
if>
foreach>
if>
sql>
<insert id="insert" parameterType="com.xy.pay.main.dao.model.SysUser" useGeneratedKeys="true" keyProperty="id">
INSERT INTO sys_user (
name
<if test="password != null">
,password
if>
<if test="enabled != null">
,enabled
if>
<if test="phone != null">
,phone
if>
<if test="uservos != null">
,uservos
if>
<if test="parent != null and parent.id != null">
,parent_id
if>
)
VALUES (
#{name}
<if test="password != null">
,#{password}
if>
<if test="enabled != null">
,#{enabled}
if>
<if test="phone != null">
,#{phone}
if>
<if test="uservos != null">
,#{uservos,typeHandler=com.xy.pay.main.dao.handler.ObjectListJsonTypeHandler}
if>
<if test="parent != null and parent.id != null">
,#{parent.id}
if>
)
insert>
<sql id="updateSet">
<trim suffixOverrides=",">
<if test="password != null">
password = #{password},
if>
<if test="enabled != null">
enabled = #{enabled},
if>
<if test="phone != null">
phone = #{phone},
if>
<if test="uservos != null">
uservos = #{uservos,typeHandler=com.xy.pay.main.dao.handler.ObjectListJsonTypeHandler},
if>
trim>
sql>
<update id="update" parameterType="com.xy.pay.main.dao.model.SysUser">
UPDATE sys_user SET
<include refid="updateSet"/>
WHERE id = #{id}
update>
<update id="updateByCriteria" parameterType="map">
UPDATE sys_user SET
<include refid="updateSet"/>
WHERE
<include refid="baseWhere"/>
update>
<select id="select" parameterType="map" resultMap="mapper">
SELECT
<include refid="columns"/>
FROM sys_user
<include refid="where"/>
<include refid="orderBy"/>
select>
<select id="selectCount" parameterType="map" resultType="long">
SELECT count(*) from sys_user
<where>
<include refid="baseWhere"/>
where>
select>
<update id="delete" parameterType="map">
DELETE FROM sys_user
WHERE
<include refid="baseWhere"/>
update>
mapper>
关于mysql json类型查询的语法请看这里