mybatis-plus多表分页查询最佳实现方法(非常简单)

    <mybatis-plus.version>3.5.1</mybatis-plus.version>
    <connector.version>8.0.18</connector.version>

            <!--    ================mybatis-plus==================        -->
            <!--mybatis-plus 持久层-->
            <dependency>
                <groupId>com.baomidou</groupId>
                <artifactId>mybatis-plus-boot-starter</artifactId>
                <version>${mybatis-plus.version}</version>
            </dependency>
            <!-- mybatis plus 代码生成器依赖 -->
            <dependency>
                <groupId>com.baomidou</groupId>
                <artifactId>mybatis-plus-generator</artifactId>
                <version>${mybatis-plus.version}</version>
            </dependency>
            <!--    ================mybatis-plus==================        -->
            <!--mysql-->
            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <version>${connector.version}</version>
            </dependency>

@Configuration
public class MPConfig {
    /**
     * 分页插件
     */
    @Bean
    public MybatisPlusInterceptor mybatisPlusInterceptor() {
        MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();
        //乐观锁
        //interceptor.addInnerInterceptor(new OptimisticLockerInnerInterceptor());
        //分页锁
        interceptor.addInnerInterceptor(new PaginationInnerInterceptor(DbType.MYSQL));
        return interceptor;
    }
}

package com.dxf.common.utils;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import io.swagger.annotations.ApiModelProperty;
import io.swagger.annotations.ApiParam;
import springfox.documentation.annotations.ApiIgnore;
import java.util.List;
public class PageParam<T> extends Page<T> {
    /**
     * 查询数据列表
     */
    @ApiParam(hidden = true)
    private List<T> records;
    /**
     * 总数
     */
    @ApiParam(hidden = true)
    private long total = 0;
    /**
     * 每页显示条数，默认 10
     */
    @ApiParam(value = "每页大小，默认10",required = false, defaultValue = "10")
    private long size = 10;
    /**
     * 当前页
     */
    @ApiParam(value = "当前页，默认1",required = false,defaultValue = "1")
    private long current = 1;
    /**
     * 是否进行 count 查询
     */
    @ApiParam(hidden = true)
    private boolean isSearchCount = true;
    @Override
    @ApiParam(hidden = true)
    public List<T> getRecords() {
        return this.records;
    }
    @Override
    public Page<T> setRecords(List<T> records) {
        this.records = records;
        return this;
    }
    @Override
    public long getTotal() {
        return this.total;
    }
    @Override
    public Page<T> setTotal(long total) {
        this.total = total;
        return this;
    }
    @ApiParam(hidden = true)
    public boolean getSearchCount() {
        if (total < 0) {
            return false;
        }
        return isSearchCount;
    }
    @Override
    @ApiParam(hidden = true)
    public boolean isSearchCount() {
        if (total < 0) {
            return false;
        }
        return isSearchCount;
    }
    @Override
    public Page<T> setSearchCount(boolean isSearchCount) {
        this.isSearchCount = isSearchCount;
        return this;
    }
    @Override
    public long getSize() {
        return this.size;
    }
    @Override
    public Page<T> setSize(long size) {
        this.size = size;
        return this;
    }
    @Override
    public long getCurrent() {
        return this.current;
    }
    @Override
    public Page<T> setCurrent(long current) {
        this.current = current;
        return this;
    }
}

import org.apache.ibatis.annotations.Param;
public interface SysRoleMapper extends BaseMapper<SysRole> {
    IPage<SysRole> searchPage(PageParam<SysRole> pageParam, @Param("name") String name);
}

<?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.dxf.data.mapper.SysRoleMapper">
    <select id="searchPage" resultType="com.dxf.data.entity.SysRole">
        SELECT r.id,r.name,r.status,r.role_sort, a.name create_by ,r.create_time,r.update_time,r.remark
        FROM sys_role r left join sys_user a on r.create_by=a.id
        <where>
            <if test="name != null and name != ''">
                r.name like concat(#{name},'%')
            </if>
        </where>
        order by r.role_sort
    </select>
</mapper>

@RestController
@RequestMapping("/admin/role")
@Api(tags  = "SysRoleControllr|角色控制器")
public class SysRoleController {
    @Autowired
    SysRoleService roleService;
    @GetMapping("/page")
    @ApiOperation("角色列表分页查询")
    public ResultJson page(PageParam<SysRole> pageParam,String likeKey) {
        IPage<SysRole> iPage = roleService.searchPage(pageParam,likeKey);
        Map<String, Object> map = new HashMap<>();
        map.put("rows",iPage.getRecords());
        map.put("total",iPage.getTotal());
        return ResultJson.ok().data(map);
    }
public interface SysRole
}
Service extends IService<SysRole> {
    /**
     * 分页查询角色
     */
    IPage<SysRole> searchPage(PageParam<SysRole> pageParam,String name);
}
@Service
public class SysRoleServiceImpl extends ServiceImpl<SysRoleMapper, SysRole> implements SysRoleService {
    @Override
    public IPage<SysRole> searchPage(PageParam<SysRole> pageParam,String name) {
        return baseMapper.searchPage(pageParam,name);
    }
}