6 Mybatis Plus and 和 or，分页Page使用

Mybatis Plus 查询条件中and和or的使用：

​ mybatis plus 查询条件默认是使用and拼接的，有的情况下我们需要自定义查询条件顺序，希望用到（）或者or来进行sql语句优先级查询，所以需要 自己处理 Wrapper查询条件：

1、使用LambdaQueryWrapper进行条件封装：

• 当有多个查询条件时，or()最好结合and()使用

• 当有两个查询条件时，or()可以直接使用；

        LambdaQueryWrapper<VipManagement> vipManagementLambdaQueryWrapper = Wrappers.<VipManagement>lambdaQuery()
                .like(StringUtils.isNotBlank(vipManagementDto.getVipCarNumber()), VipManagement::getVipCarNumber, vipManagementDto.getVipCarNumber())
                .like(StringUtils.isNotBlank(vipManagementDto.getVipName()), VipManagement::getVipName, vipManagementDto.getVipName())
                .like(StringUtils.isNotBlank(vipManagementDto.getVipSchemeName()), VipManagement::getVipSchemeName, vipManagementDto.getVipSchemeName())
                .like(StringUtils.isNotBlank(vipManagementDto.getCauseTypeName()), VipManagement::getCauseTypeName, vipManagementDto.getCauseTypeName())
                .eq(vipManagementDto.getStatus() != null, VipManagement::getStatus, vipManagementDto.getStatus())
                .orderByDesc(VipManagement::getCreateTime);
        List<Long> marketParkingId = parkingService.getMarketParkingId(vipManagementDto.getMarketId());
        if (marketParkingId.size() == 0) {
            return PageBean.builder().build();
        }
        vipManagementLambdaQueryWrapper.and((vipManagementLambdaQueryWrapper1) -> {
            marketParkingId.stream().forEach(parkingId -> {
                vipManagementLambdaQueryWrapper1.like(VipManagement::getParkingId, parkingId).or();
            });
        });

2、分简单分页模型：Page

• page.getCurrent()	//当前页，默认 1
  

• page.getSize()		//每页显示条数，默认 10
  

• page.getTotal()		//总条数
  

• page.getRecords()	//分页记录列表
  

Page<Parking> page = new Page<>();
if (parkingDto.getPageNum() != null || parkingDto.getPageSize() != null) {
    page.setCurrent(parkingDto.getPageNum()).setSize(parkingDto.getPageSize());
}
Page<Parking> parkingPage = this.page(page, Wrappers.<Parking>lambdaQuery()
        .like(parkingDto.getTypeId() != null, Parking::getTypeId, parkingDto.getTypeId())
        .eq(parkingDto.getSupplierId() != null, Parking::getSupplierId, parkingDto.getSupplierId())
        .eq(parkingDto.getStatus() != null, Parking::getStatus, parkingDto.getStatus())
        .eq(parkingDto.getPlateId() != null, Parking::getPlateId, parkingDto.getPlateId())
        .eq(parkingDto.getMarketId() != null, Parking::getMarketId, parkingDto.getMarketId())
        .orderByDesc(Parking::getCreateTime).and(StringUtils.isNotBlank(parkingDto.getParkingName()), lambdaQueryWrapper -> {
            lambdaQueryWrapper.like(Parking::getParkingName, parkingDto.getParkingName()).or().like(Parking::getParkingNo, parkingDto.getParkingName());
        }));