后端开发4——mybatis操作数据库模板

1 controller——xxxController.java

点击展开

package com.wrj.controller;

import …

//当前类注册为控制器类并添加到Bean列表
//当需要返回视图页面时需要使用Controller注解，需要返回序列化数据时使用RestController注解
@RestController
//映射HTTP请求，RequestMapping不限制请求类型，限制时可使用PostMapping、GetMappering等
@RequestMapping("/personUser")
public class PersonUserController {
    //从注册的Bean列表中自动匹配属性注入对象
    @Autowired
    private IPersonUserService personUserService;
    //请求处理接口
    @RequestMapping("/hello")
    public String hello(){
        try {
            PersonUser personUser = personUserService.selectPersonUserById("07f1951631d44fb2a03256841fb14c0d");
            if(personUser != null)
                return "loginid: "+personUser.getLoginId().toString();
        }
        catch (Exception e){
            return e.getMessage();
        }
        return "hello world";
    }
}

2 domain——xxx.java

映射数据库表的实体类，与数据表对应；

点击展开

<?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.wrj.mapper.PersonUserMapper">
    <resultMap type="com.wrj.domain.PersonUser" id="PersonUserResult">
        <result property="id"    column="id"    />
        ……
    </resultMap>

    <sql id="selectPersonUserVo">
        select id, …… from person_user
    </sql>

    <select id="selectPersonUserList" parameterType="com.wrj.domain.PersonUser" resultMap="PersonUserResult">
        <include refid="selectPersonUserVo"/>
        <where>
            <if test="loginId != null "> and login_id = #{loginId}</if>
            ……
        </where>
    </select>

    <select id="selectPersonUserById" parameterType="String" resultMap="PersonUserResult">
        <include refid="selectPersonUserVo"/>
        where id = #{id}
    </select>

    <insert id="insertPersonUser" parameterType="com.wrj.domain.PersonUser">
        insert into person_user
        <trim prefix="(" suffix=")" suffixOverrides=",">
            <if test="id != null and id != ''">id,</if>
            ……
        </trim>
        <trim prefix="values (" suffix=")" suffixOverrides=",">
            <if test="id != null and id != ''">#{id},</if>
            ……
        </trim>
    </insert>

    <update id="updatePersonUser" parameterType="com.wrj.domain.PersonUser">
        update person_user
        <trim prefix="SET" suffixOverrides=",">
            <if test="loginId != null">login_id = #{loginId},</if>
            ……
        </trim>
        where id = #{id}
    </update>

    <delete id="deletePersonUserById" parameterType="String">
        delete from person_user where id = #{id}
    </delete>
</mapper>

5 resources——mapper——moduleName——xxxMapper.xml

点击展开

<?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.wrj.mapper.PersonUserMapper">
    <resultMap type="com.wrj.domain.PersonUser" id="PersonUserResult">
        <result property="id"    column="id"    />
        ……
    </resultMap>

    <sql id="selectPersonUserVo">
        select id, …… from person_user
    </sql>

    <select id="selectPersonUserList" parameterType="com.wrj.domain.PersonUser" resultMap="PersonUserResult">
        <include refid="selectPersonUserVo"/>
        <where>
            <if test="loginId != null "> and login_id = #{loginId}</if>
            ……
        </where>
    </select>

    <select id="selectPersonUserById" parameterType="String" resultMap="PersonUserResult">
        <include refid="selectPersonUserVo"/>
        where id = #{id}
    </select>

    <insert id="insertPersonUser" parameterType="com.wrj.domain.PersonUser">
        insert into person_user
        <trim prefix="(" suffix=")" suffixOverrides=",">
            <if test="id != null and id != ''">id,</if>
            ……
        </trim>
        <trim prefix="values (" suffix=")" suffixOverrides=",">
            <if test="id != null and id != ''">#{id},</if>
            ……
        </trim>
    </insert>

    <update id="updatePersonUser" parameterType="com.wrj.domain.PersonUser">
        update person_user
        <trim prefix="SET" suffixOverrides=",">
            <if test="loginId != null">login_id = #{loginId},</if>
            ……
        </trim>
        where id = #{id}
    </update>

    <delete id="deletePersonUserById" parameterType="String">
        delete from person_user where id = #{id}
    </delete>
</mapper>