springboot集成Mybatis-plus-join-boot-start详解

<dependency>
    <groupid>com.baomidou</groupid>
    <artifactid>mybatis-plus-boot-starter</artifactid>
    <version>3.5.5</version>
</dependency>
<dependency>
    <groupid>com.github.yulichang</groupid>
    <artifactid>mybatis-plus-join-boot-starter</artifactid>
    <version>1.4.13</version>
</dependency>

create table `sys_user` (
                            `id` bigint unsigned not null auto_increment comment 'id',
                            `dept_id` bigint default null comment '部门id',
                            `user_name` varchar(30) character set utf8mb4 collate utf8mb4_general_ci not null comment '账号',
                            `password` varchar(100) character set utf8mb4 collate utf8mb4_general_ci not null default '' comment '密码',
                            `nick_name` varchar(30) character set utf8mb4 collate utf8mb4_general_ci not null default '' comment '昵称',
                            `email` varchar(50) character set utf8mb4 collate utf8mb4_general_ci default '' comment '用户邮箱',
                            `phone_number` varchar(11) character set utf8mb4 collate utf8mb4_general_ci default '' comment '手机号码',
                            `sex` char(1) character set utf8mb4 collate utf8mb4_general_ci default '0' comment '用户性别（0男 1女）',
                            `avatar` varchar(100) character set utf8mb4 collate utf8mb4_general_ci default '' comment '头像地址',
                            `status` char(1) character set utf8mb4 collate utf8mb4_general_ci not null default '0' comment '帐号状态（0正常 1停用）',
                            `remark` varchar(500) character set utf8mb4 collate utf8mb4_general_ci default null comment '备注',
                            `deleted` tinyint(1) not null default '0' comment '删除标志',
                            `version` int default null comment '乐观锁',
                            `create_by` bigint default null comment '创建人',
                            `create_time` datetime default null comment '创建时间',
                            `update_by` bigint default null comment '更新人',
                            `update_time` datetime default null comment '更新时间',
                            primary key (`id`) using btree
) engine=innodb auto_increment=1 default charset=utf8mb4 collate=utf8mb4_general_ci row_format=dynamic comment='用户信息';

create table `sys_dept` (
                            `id` bigint not null auto_increment comment '部门id',
                            `parent_id` bigint default '0' comment '父部门id',
                            `dept_name` varchar(30) character set utf8mb4 collate utf8mb4_general_ci default '' comment '部门名称',
                            `order_num` int default '0' comment '显示顺序',
                            `status` char(1) character set utf8mb4 collate utf8mb4_general_ci default '0' comment '部门状态（0正常 1停用）',
                            `remark` varchar(255) character set utf8mb4 collate utf8mb4_general_ci default null comment '备注',
                            `deleted` tinyint(1) not null default '0' comment '删除标志',
                            `create_by` bigint default null comment '创建人',
                            `create_time` datetime default null comment '创建时间',
                            `update_by` bigint default null comment '更新人',
                            `update_time` datetime default null comment '更新时间',
                            primary key (`id`) using btree
) engine=innodb auto_increment=1 default charset=utf8mb4 collate=utf8mb4_general_ci row_format=dynamic comment='部门信息';

public interface sysusermapper extends mpjbasemapper<sysuser> {
}
public interface sysdeptmapper extends mpjbasemapper<sysdept> {
}

@service
public class sysuserserviceimpl extends mpjbaseserviceimpl<sysusermapper, sysuser> implements sysuserservice {
@autowired
private sysusermapper sysusermapper;

/**
 * 测试：列表多表联查
 *
 * @return
 */
@override
public list<sysuser> sysuserlist() {
    //构建查询条件
    mpjlambdawrapper<sysuser> querywrapper = new mpjlambdawrapper<>();
    //联查
    querywrapper.selectall(sysuser.class)
            .select(sysdept::getdeptname)
            .leftjoin(sysdept.class, sysdept::getid, sysuser::getdeptid);
    //返
    return list(querywrapper);
}

/**
 * 删除
 *
 * @param id
 * @return
 */
@override
public boolean deletebyid(long id) {
    //创建一个删除条件
    deletejoinwrapper<sysuser> eq = joinwrappers.delete(sysuser.class)
            //与dept相连
            .leftjoin(sysdept.class, sysdept::getid, sysuser::getdeptid)
            //根据id删除
            .eq(sysuser::getid, id);
    return deletejoin(eq);
}
}

public interface sysuserservice extends mpjbaseservice<sysuser> {
/**
 * 列表 ：多表
 *
 * @return
 */
list<sysuser> sysuserlist();

/**
 * 删除
 *
 * @param id
 * @return
 */
boolean deletebyid(long id);
}

@restcontroller
@requestmapping("/sysuser")
public class sysusercontroller {
    @autowired
    private sysuserservice sysuserservice;

    /**
     * 列表 ：多表
     *
     * @return
     */
    @getmapping("/sysuserlist")
    public list<sysuser> sysuserlist() {
        return sysuserservice.sysuserlist();
    }

    /**
     * 删除
     *
     * @param id
     * @return
     */
    @deletemapping("/deletebyid/{id}")
    public boolean deletebyid(@pathvariable("id") long id) {
        return sysuserservice.deletebyid(id);
    }
}