笔记:使用mongo聚合查询(一开始根本没接触过mongo，一点一点慢慢的查资料完成了工作需求)
需求：在订单表中，根据buyerNick分组，统计每个buyerNick的电话、地址、支付总金额以及总商品数，返回结果是CustomerDetail。
/*
* project:列出所有本次查询的字段，包括查询条件的字段和需要搜索的字段；
* match:搜索条件criteria
* unwind：某一个字段是集合，将该字段分解成数组
* group：分组的字段，以及聚合相关查询
* sum：求和(同sql查询)
* count：数量(同sql查询)
* as:别名(同sql查询)
* addToSet：将符合的字段值添加到一个集合或数组中
* sort：排序
* skip&limit：分页查询
*/
public List<CustomerDetail> customerDetailList(Integer pageNum,String userId,String buyerNick,String itemId,List<String> phones) throws Exception{
Criteria criteria = Criteria.where("userId").is(userId);
Integer pageSize = 10;
Integer startRows = (pageNum - 1) * pageSize;
if(buyerNick != null && !"".equals(buyerNick)){
criteria.and("buyerNick").is(buyerNick);
}
if(phones != null && phones.size() > 0){
criteria.and("mobile").in(phoneList);
}
if(itemId != null && !"".equals(itemId)){
criteria.and("orders.numIid").is(itemId);
}
Aggregation customerAgg = Aggregation.newAggregation(
Aggregation.project("buyerNick","payment","num","tid","userId","address","mobile","orders"),
Aggregation.match(criteria),
Aggregation.unwind("orders"),
Aggregation.group("buyerNick").first("buyerNick").as("buyerNick").first("mobile").as("mobile").
first("address").as("address").sum("payment").as("totalPayment").sum("num").as("itemNum").count().as("orderNum"),
Aggregation.sort(new Sort(new Sort.Order(Sort.Direction.DESC, "totalPayment"))),
Aggregation.skip(startRows),
Aggregation.limit(pageSize)
);
List<CustomerDetail> customerList = tradeRepository.findAggregateList(new Query(criteria), userId, customerAgg,CustomerDetail.class);
return customerList;
}
public <T> List<T> findAggregateList(Query query,String userNickName, Aggregation aggregation,Class<T> clazz) {
AggregationResults<T> aggregate = this.mongoTemplate.aggregate(aggregation, collectionName, clazz);
List<T> customerDetails = aggregate.getMappedResults();
return customerDetails;
}
Trade表：
public class TradeInfo{
private String tid;//订单id
private Double payment;//支付金额
private String buyerNick;//买家昵称
private String address;//地址
private String mobile;//手机号
private Long num;//购买商品数量
private List<order> orders;子订单
}
CustomerDetail：
public class CustomerDetail{
private String buyerNick;//买家昵称
private Double totalPayment;//订单金额
private Integer orderNum;//订单数
private Integer itemNum;//商品数
private String address;//地址
}
OVER!