简介
MyBatis-Plus (opens new window)(简称 MP)是一个 MyBatis (opens new window)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。
快速开始
添加依赖
全新的 MyBatis-Plus 3.0 版本基于 JDK8,提供了 lambda 形式的调用,所以安装集成 MP3.0 要求如下:
JDK 8+
Maven or Gradle
Spring Boot项目
maven:
<dependency><groupId>com.baomidou</groupId><artifactId>mybatis-plus-boot-starter</artifactId><version>最新版本</version>
</dependency>
Spring 项目
maven:
<dependency><groupId>com.baomidou</groupId><artifactId>mybatis-plus</artifactId><version>最新版本</version>
</dependency>
配置
在 application.yml 配置文件中添加 H2 数据库的相关配置:
# DataSource Config
spring:datasource:driver-class-name: org.h2.Driverschema: classpath:db/schema-h2.sqlusername: rootpassword: testsql:init:schema-locations: classpath:db/schema-h2.sqldata-locations: classpath:db/data-h2.sql
在 Spring Boot 启动类中添加 @MapperScan 注解,扫描 Mapper 文件夹:
@SpringBootApplication
@MapperScan("com.baomidou.mybatisplus.samples.quickstart.mapper")
public class Application {public static void main(String[] args) {SpringApplication.run(Application.class, args);}}
Page分页
方式一:
使用mybatis-plus 的 Service page 接口
@GetMapping("/pageList")@ApiOperation(value = "分页列表", notes = "query和user")public R<IPage<User>> pageList(@ApiIgnore User user, Query query) {//无条件分页IPage<User> pages = userService.page(Condition.getPage(query));//有条件分页IPage<User> pages = userService.page(Condition.getPage(query), Wrappers.lambdaQuery(user));return R.data(pages);}
方式二:
自定义sql分页
controller层代码:
@GetMapping("/pageList")@ApiOperation(value = "分页列表", notes = "query和user")public R<IPage<User>> pageList(@ApiIgnore User user, Query query) {IPage<User> pages = userService.selectUserPage(Condition.getPage(query), user);return R.data(pages);}
service 里调用自定义分页sql mapper方法
@Overridepublic IPage<User> selectUserPage(IPage<User> page, User user) {return page.setRecords(baseMapper.selectUserPage(page, user));}
定义mapper分页接口:
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.gis.spacedata.bladex.domain.entity.system.User;
import org.apache.ibatis.annotations.Param;import java.util.List;import java.util.List;public interface UserMapper extends BaseMapper<User> {List<User> selectUserPage(IPage<User> page, @Param("user") User user);}
mybatis xml:
<select id="selectUserPage" resultMap="userResultMap">select * from blade_user where is_deleted = 0<if test="user.tenantId!=null and user.tenantId != ''">and tenant_id = #{user.tenantId}</if><if test="user.account!=null and user.account != ''">and account like CONCAT('%',#{user.account},'%')</if><if test="user.realName!=null and user.realName != ''">and real_name like CONCAT('%',#{user.realName},'%')</if><if test="user.roleId!=null and user.roleId != ''">and CAST(#{user.roleId} AS VARCHAR)= ANY(STRING_TO_ARRAY(role_id, ','))</if>ORDER BY id</select>
Condition 工具类:
import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import org.springblade.core.launch.constant.TokenConstant;
import org.springblade.core.tool.support.Kv;
import org.springblade.core.tool.utils.BeanUtil;
import org.springblade.core.tool.utils.Func;import java.util.Map;/*** 分页工具** @author Chill*/
public class Condition {/*** 转化成mybatis plus中的Page** @param query 查询条件* @return IPage*/public static <T> IPage<T> getPage(Query query) {Page<T> page = new Page<>(Func.toInt(query.getCurrent(), 1), Func.toInt(query.getSize(), 10));page.setAsc(Func.toStrArray(SqlKeyword.filter(query.getAscs())));page.setDesc(Func.toStrArray(SqlKeyword.filter(query.getDescs())));return page;}/*** 获取mybatis plus中的QueryWrapper** @param entity 实体* @param <T> 类型* @return QueryWrapper*/public static <T> QueryWrapper<T> getQueryWrapper(T entity) {return new QueryWrapper<>(entity);}/*** 获取mybatis plus中的QueryWrapper** @param query 查询条件* @param clazz 实体类* @param <T> 类型* @return QueryWrapper*/public static <T> QueryWrapper<T> getQueryWrapper(Map<String, Object> query, Class<T> clazz) {Kv exclude = Kv.create().set(TokenConstant.HEADER, TokenConstant.HEADER).set("current", "current").set("size", "size").set("ascs", "ascs").set("descs", "descs");return getQueryWrapper(query, exclude, clazz);}/*** 获取mybatis plus中的QueryWrapper** @param query 查询条件* @param exclude 排除的查询条件* @param clazz 实体类* @param <T> 类型* @return QueryWrapper*/public static <T> QueryWrapper<T> getQueryWrapper(Map<String, Object> query, Map<String, Object> exclude, Class<T> clazz) {exclude.forEach((k, v) -> query.remove(k));QueryWrapper<T> qw = new QueryWrapper<>();qw.setEntity(BeanUtil.newInstance(clazz));SqlKeyword.buildCondition(query, qw);return qw;}}
方式三:
使用mybatis-plus的Db类
说明:
使用静态调用的方式,执行CRUD方法,避免Spring环境下Service循环注入、简洁代码,提升效率
需要项目中已注入对应实体的BaseMapper
完整使用方式见: 测试用例(opens new window)
对于参数为Wrapper的,需要在Wrapper中传入Entity或者EntityClass供寻找对应的Mapper
不建议在循环中调用,如果是批量保存,建议将数据构造好后使用 Db.saveBatch(数据) 保存
@Testvoid testPage() {IPage<Entity> page = Db.page(new Page<>(1, 1), Entity.class);Assertions.assertEquals(2, page.getTotal());page = Db.page(new Page<>(1, 1), Wrappers.lambdaQuery(Entity.class));Assertions.assertEquals(1, page.getRecords().size());}