SpringBoot集成PostgreSQL - 基于MyBatis-Plus方式
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SpringBoot集成PostgreSQL - 基于MyBatis-Plus方式
前文介绍SpringBoot+MyBatis-Plus+MySQL的集成,本文主要介绍SpringBoot+MyBatis-Plus+PostgreSQL的集成。@pdai
知识准备
MyBatis-Plus(简称 MP)是一个 MyBatis的增强工具,在 MyBatis 的基础上只做增强不做改变,为简化开发、提高效率而生。
- SpringBoot集成MySQL - MyBatis-Plus方式
 - MyBatis-Plus(简称 MP)是一个 MyBatis的增强工具,在 MyBatis 的基础上只做增强不做改变,为简化开发、提高效率而生。MyBatis-Plus在国内也有很多的用户,本文主要介绍MyBatis-Plus和SpringBoot的集成。
 
简单示例
这里保持我们前文同样的结构的数据库(略有更改), 并向你展示SpringBoot + MyBatis-Plus的使用等。
准备DB和依赖配置
创建PostgreSQL的Database test_db_pg, 导入SQL 文件如下
    CREATE TABLE public.tb_user
    (
        id bigint NOT NULL,
        user_name character varying(255) COLLATE pg_catalog."default" NOT NULL,
        password character varying(255) COLLATE pg_catalog."default" NOT NULL,
        email character varying(255) COLLATE pg_catalog."default",
        phone_number bigint,
        description character varying(255) COLLATE pg_catalog."default",
        create_time timestamp(6) with time zone,
        update_time timestamp(6) with time zone,
        CONSTRAINT tb_user_pkey PRIMARY KEY (id)
    )
    CREATE TABLE public.tb_role
    (
        id bigint NOT NULL,
        name character varying(255) COLLATE pg_catalog."default",
        role_key character varying(255) COLLATE pg_catalog."default",
        description character varying(255) COLLATE pg_catalog."default",
        create_time timestamp(6) with time zone,
        update_time timestamp(6) with time zone,
        CONSTRAINT tb_role_pkey PRIMARY KEY (id)
    )
    CREATE TABLE public.tb_user_role
    (
        user_id bigint NOT NULL,
        role_id bigint NOT NULL
    )
引入maven依赖
    <dependency>
        <groupId>org.postgresql</groupId>
        <artifactId>postgresql</artifactId>
        <version>42.2.18</version>
    </dependency>
    <dependency>
        <groupId>com.baomidou</groupId>
        <artifactId>mybatis-plus-boot-starter</artifactId>
        <version>3.5.1</version>
    </dependency>
增加yml配置
    spring:
      datasource:
        url: jdbc:postgresql://localhost:5432/test_db_pg
        username: postgres
        password: bfXa4Pt2lUUScy8jakXf
    mybatis-plus:
      configuration:
        cache-enabled: true
        use-generated-keys: true
        default-executor-type: REUSE
        use-actual-param-name: true
定义dao
(也就是你自己的xxxMapper) RoleDao
    package tech.pdai.springboot.postgre.mybatisplus.dao;
    import com.baomidou.mybatisplus.core.mapper.BaseMapper;
    import tech.pdai.springboot.postgre.mybatisplus.entity.Role;
    /** * @author pdai */
    public interface IRoleDao extends BaseMapper<Role> {
    }
UserDao
    package tech.pdai.springboot.postgre.mybatisplus.dao;
    import java.util.List;
    import com.baomidou.mybatisplus.core.mapper.BaseMapper;
    import tech.pdai.springboot.postgre.mybatisplus.entity.User;
    import tech.pdai.springboot.postgre.mybatisplus.entity.query.UserQueryBean;
    /** * @author pdai */
    public interface IUserDao extends BaseMapper<User> {
        List<User> findList(UserQueryBean userQueryBean);
    }
这里你也同时可以支持BaseMapper方式和自己定义的xml的方法(比较适用于关联查询),比如findList是自定义xml配置
    <?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="tech.pdai.springboot.postgre.mybatisplus.dao.IUserDao">
    	<resultMap type="tech.pdai.springboot.postgre.mybatisplus.entity.User" id="UserResult">
    		<id property="id" column="id" />
    		<result property="userName" column="user_name" />
    		<result property="password" column="password" />
    		<result property="email" column="email" />
    		<result property="phoneNumber" column="phone_number" />
    		<result property="description" column="description" />
    		<result property="createTime" column="create_time" typeHandler="tech.pdai.springboot.postgre.mybatisplus.config.PgTimestampZTypeHandler" />
    		<result property="updateTime" column="update_time" typeHandler="tech.pdai.springboot.postgre.mybatisplus.config.PgTimestampZTypeHandler" />
    		<collection property="roles" ofType="tech.pdai.springboot.postgre.mybatisplus.entity.Role">
    			<result property="id" column="id" />
    			<result property="name" column="name" />
    			<result property="roleKey" column="role_key" />
    			<result property="description" column="description" />
    			<result property="createTime" column="create_time" typeHandler="tech.pdai.springboot.postgre.mybatisplus.config.PgTimestampZTypeHandler" />
    			<result property="updateTime" column="update_time" typeHandler="tech.pdai.springboot.postgre.mybatisplus.config.PgTimestampZTypeHandler" />
    		</collection>
    	</resultMap>
    	
    	<sql id="selectUserSql">
            select u.id, u.password, u.user_name, u.email, u.phone_number, u.description, u.create_time, u.update_time, r.name, r.role_key, r.description, r.create_time, r.update_time
    		from tb_user u
    		left join tb_user_role ur on u.id=ur.user_id
    		inner join tb_role r on ur.role_id=r.id
        </sql>
    	
    	<select id="findList" parameterType="tech.pdai.springboot.postgre.mybatisplus.entity.query.UserQueryBean" resultMap="UserResult">
    		<include refid="selectUserSql"/>
    		where u.id != 0
    		<if test="userName != null and userName != ''">
    			AND u.user_name like concat('%', #{user_name}, '%')
    		</if>
    		<if test="description != null and description != ''">
    			AND u.description like concat('%', #{description}, '%')
    		</if>
    		<if test="phoneNumber != null and phoneNumber != ''">
    			AND u.phone_number like concat('%', #{phoneNumber}, '%')
    		</if>
    		<if test="email != null and email != ''">
    			AND u.email like concat('%', #{email}, '%')
    		</if>
    	</select>
    	
    </mapper> 
定义Service接口和实现类
UserService接口
    package tech.pdai.springboot.postgre.mybatisplus.service;
    import java.util.List;
    import com.baomidou.mybatisplus.extension.service.IService;
    import tech.pdai.springboot.postgre.mybatisplus.entity.User;
    import tech.pdai.springboot.postgre.mybatisplus.entity.query.UserQueryBean;
    /** * @author pdai */
    public interface IUserService extends IService<User> {
        List<User> findList(UserQueryBean userQueryBean);
    }
User Service的实现类
    package tech.pdai.springboot.postgre.mybatisplus.service.impl;
    import java.util.List;
    import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
    import org.springframework.stereotype.Service;
    import tech.pdai.springboot.postgre.mybatisplus.dao.IUserDao;
    import tech.pdai.springboot.postgre.mybatisplus.entity.User;
    import tech.pdai.springboot.postgre.mybatisplus.entity.query.UserQueryBean;
    import tech.pdai.springboot.postgre.mybatisplus.service.IUserService;
    @Service
    public class UserDoServiceImpl extends ServiceImpl<IUserDao, User> implements IUserService {
        @Override
        public List<User> findList(UserQueryBean userQueryBean) {
            return baseMapper.findList(userQueryBean);
        }
    }
Role Service 接口
    package tech.pdai.springboot.postgre.mybatisplus.service;
    import java.util.List;
    import com.baomidou.mybatisplus.extension.service.IService;
    import tech.pdai.springboot.postgre.mybatisplus.entity.Role;
    import tech.pdai.springboot.postgre.mybatisplus.entity.query.RoleQueryBean;
    public interface IRoleService extends IService<Role> {
        List<Role> findList(RoleQueryBean roleQueryBean);
    }
Role Service 实现类
    package tech.pdai.springboot.postgre.mybatisplus.service.impl;
    import java.util.List;
    import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
    import org.apache.commons.lang3.StringUtils;
    import org.springframework.stereotype.Service;
    import tech.pdai.springboot.postgre.mybatisplus.dao.IRoleDao;
    import tech.pdai.springboot.postgre.mybatisplus.entity.Role;
    import tech.pdai.springboot.postgre.mybatisplus.entity.query.RoleQueryBean;
    import tech.pdai.springboot.postgre.mybatisplus.service.IRoleService;
    @Service
    public class RoleDoServiceImpl extends ServiceImpl<IRoleDao, Role> implements IRoleService {
        @Override
        public List<Role> findList(RoleQueryBean roleQueryBean) {
            return lambdaQuery().like(StringUtils.isNotEmpty(roleQueryBean.getName()), Role::getName, roleQueryBean.getName())
                    .like(StringUtils.isNotEmpty(roleQueryBean.getDescription()), Role::getDescription, roleQueryBean.getDescription())
                    .like(StringUtils.isNotEmpty(roleQueryBean.getRoleKey()), Role::getRoleKey, roleQueryBean.getRoleKey())
                    .list();
        }
    }
controller
User Controller
    package tech.pdai.springboot.postgre.mybatisplus.controller;
    import java.time.LocalDateTime;
    import java.util.List;
    import io.swagger.annotations.ApiOperation;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.PathVariable;
    import org.springframework.web.bind.annotation.PostMapping;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    import tech.pdai.springboot.postgre.mybatisplus.entity.User;
    import tech.pdai.springboot.postgre.mybatisplus.entity.query.UserQueryBean;
    import tech.pdai.springboot.postgre.mybatisplus.entity.response.ResponseResult;
    import tech.pdai.springboot.postgre.mybatisplus.service.IUserService;
    /** * @author pdai */
    @RestController
    @RequestMapping("/user")
    public class UserController {
        @Autowired
        private IUserService userService;
        /** * @param user user param * @return user */
        @ApiOperation("Add/Edit User")
        @PostMapping("add")
        public ResponseResult<User> add(User user) {
            if (user.getId() == null) {
                user.setCreateTime(LocalDateTime.now());
            }
            user.setUpdateTime(LocalDateTime.now());
            userService.save(user);
            return ResponseResult.success(userService.getById(user.getId()));
        }
        /** * @return user list */
        @ApiOperation("Query User One")
        @GetMapping("edit/{userId}")
        public ResponseResult<User> edit(@PathVariable("userId") Long userId) {
            return ResponseResult.success(userService.getById(userId));
        }
        /** * @return user list */
        @ApiOperation("Query User List")
        @GetMapping("list")
        public ResponseResult<List<User>> list(UserQueryBean userQueryBean) {
            return ResponseResult.success(userService.findList(userQueryBean));
        }
    }
Role Controller
    package tech.pdai.springboot.postgre.mybatisplus.controller;
    import java.util.List;
    import io.swagger.annotations.ApiOperation;
    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;
    import tech.pdai.springboot.postgre.mybatisplus.entity.Role;
    import tech.pdai.springboot.postgre.mybatisplus.entity.query.RoleQueryBean;
    import tech.pdai.springboot.postgre.mybatisplus.entity.response.ResponseResult;
    import tech.pdai.springboot.postgre.mybatisplus.service.IRoleService;
    /** * @author pdai */
    @RestController
    @RequestMapping("/role")
    public class RoleController {
        @Autowired
        private IRoleService roleService;
        /** * @return role list */
        @ApiOperation("Query Role List")
        @GetMapping("list")
        public ResponseResult<List<Role>> list(RoleQueryBean roleQueryBean) {
            return ResponseResult.success(roleService.findList(roleQueryBean));
        }
    }
分页配置
通过配置内置的MybatisPlusInterceptor拦截器。
    package tech.pdai.springboot.postgre.mybatisplus.config;
    import com.baomidou.mybatisplus.extension.plugins.MybatisPlusInterceptor;
    import com.baomidou.mybatisplus.extension.plugins.inner.PaginationInnerInterceptor;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    /** * MyBatis-plus configuration, add pagination interceptor. * * @author pdai */
    @Configuration
    public class MyBatisConfig {
        /** * inject pagination interceptor. * * @return pagination */
        @Bean
        public PaginationInnerInterceptor paginationInnerInterceptor() {
            return new PaginationInnerInterceptor();
        }
        /** * add pagination interceptor. * * @return MybatisPlusInterceptor */
        @Bean
        public MybatisPlusInterceptor mybatisPlusInterceptor() {
            MybatisPlusInterceptor mybatisPlusInterceptor = new MybatisPlusInterceptor();
            mybatisPlusInterceptor.addInnerInterceptor(paginationInnerInterceptor());
            return mybatisPlusInterceptor;
        }
    }
进一步理解
MyBatis-plus学习梳理
比较好的实践
总结下开发的过程中比较好的实践
- Mapper层:继承BaseMapper
 
    public interface IRoleDao extends BaseMapper<Role> {
    }
- Service层:继承ServiceImpl并实现对应接口
 
    public class RoleDoServiceImpl extends ServiceImpl<IRoleDao, Role> implements IRoleService {
    }
- Lambda函数式查询
 
    @Override
    public List<Role> findList(RoleQueryBean roleQueryBean) {
        return lambdaQuery().like(StringUtils.isNotEmpty(roleQueryBean.getName()), Role::getName, roleQueryBean.getName())
                .like(StringUtils.isNotEmpty(roleQueryBean.getDescription()), Role::getDescription, roleQueryBean.getDescription())
                .like(StringUtils.isNotEmpty(roleQueryBean.getRoleKey()), Role::getRoleKey, roleQueryBean.getRoleKey())
                .list();
    }
- 分页采用内置MybatisPlusInterceptor
 
    /** * inject pagination interceptor. * * @return pagination */
    @Bean
    public PaginationInnerInterceptor paginationInnerInterceptor() {
        return new PaginationInnerInterceptor();
    }
    /** * add pagination interceptor. * * @return MybatisPlusInterceptor */
    @Bean
    public MybatisPlusInterceptor mybatisPlusInterceptor() {
        MybatisPlusInterceptor mybatisPlusInterceptor = new MybatisPlusInterceptor();
        mybatisPlusInterceptor.addInnerInterceptor(paginationInnerInterceptor());
        return mybatisPlusInterceptor;
    }
- 对于复杂的关联查询
 
可以配置原生xml方式, 在其中自定义ResultMap
    <?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="tech.pdai.springboot.postgre.mybatisplus.dao.IUserDao">
    	<resultMap type="tech.pdai.springboot.postgre.mybatisplus.entity.User" id="UserResult">
    		<id property="id" column="id" />
    		<result property="userName" column="user_name" />
    		<result property="password" column="password" />
    		<result property="email" column="email" />
    		<result property="phoneNumber" column="phone_number" />
    		<result property="description" column="description" />
    		<result property="createTime" column="create_time" typeHandler="tech.pdai.springboot.postgre.mybatisplus.config.PgTimestampZTypeHandler" />
    		<result property="updateTime" column="update_time" typeHandler="tech.pdai.springboot.postgre.mybatisplus.config.PgTimestampZTypeHandler" />
    		<collection property="roles" ofType="tech.pdai.springboot.postgre.mybatisplus.entity.Role">
    			<result property="id" column="id" />
    			<result property="name" column="name" />
    			<result property="roleKey" column="role_key" />
    			<result property="description" column="description" />
    			<result property="createTime" column="create_time" typeHandler="tech.pdai.springboot.postgre.mybatisplus.config.PgTimestampZTypeHandler" />
    			<result property="updateTime" column="update_time" typeHandler="tech.pdai.springboot.postgre.mybatisplus.config.PgTimestampZTypeHandler" />
    		</collection>
    	</resultMap>
    	
    	<sql id="selectUserSql">
            select u.id, u.password, u.user_name, u.email, u.phone_number, u.description, u.create_time, u.update_time, r.name, r.role_key, r.description, r.create_time, r.update_time
    		from tb_user u
    		left join tb_user_role ur on u.id=ur.user_id
    		inner join tb_role r on ur.role_id=r.id
        </sql>
    	
    	<select id="findList" parameterType="tech.pdai.springboot.postgre.mybatisplus.entity.query.UserQueryBean" resultMap="UserResult">
    		<include refid="selectUserSql"/>
    		where u.id != 0
    		<if test="userName != null and userName != ''">
    			AND u.user_name like concat('%', #{user_name}, '%')
    		</if>
    		<if test="description != null and description != ''">
    			AND u.description like concat('%', #{description}, '%')
    		</if>
    		<if test="phoneNumber != null and phoneNumber != ''">
    			AND u.phone_number like concat('%', #{phoneNumber}, '%')
    		</if>
    		<if test="email != null and email != ''">
    			AND u.email like concat('%', #{email}, '%')
    		</if>
    	</select>
    	
    </mapper> 
除了分页插件之外还提供了哪些插件?
插件都是基于拦截器实现的,MyBatis-Plus提供了如下插件 在新窗口打开 :
- 自动分页: PaginationInnerInterceptor
 - 多租户: TenantLineInnerInterceptor
 - 动态表名: DynamicTableNameInnerInterceptor
 - 乐观锁: OptimisticLockerInnerInterceptor
 - sql 性能规范: IllegalSQLInnerInterceptor
 - 防止全表更新与删除: BlockAttackInnerInterceptor
 
示例源码
https://github.com/realpdai/tech-pdai-spring-demos