開發中使用mongoTemplate進行Aggregation聚合查詢

筆記:使用mongo聚合查詢(一開始根本沒接觸過mongo，一點一點慢慢的查資料完成了工作需求)

需求：在訂單表中，根據buyerNick分組，統計每個buyerNick的電話、地址、支付總金額以及總商品數，返回結果是CustomerDetail。

/*
 * project:列出所有本次查詢的欄位，包括查詢條件的欄位和需要搜索的欄位；
 * match:搜索條件criteria
 * unwind：某一個欄位是集合，將該欄位分解成數組
 * group：分組的欄位，以及聚合相關查詢
 * 		sum：求和(同sql查詢)
 * 		count：數量(同sql查詢)
 * 		as:別名(同sql查詢)
 * 		addToSet：將符合的欄位值添加到一個集合或數組中
 * sort：排序
 * skip&limit：分頁查詢
 */
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) {
	String collectionName = getCollectionName(userNickName);
	AggregationResults<T> aggregate = this.mongoTemplate.aggregate(aggregation, collectionName, clazz);
	List<T> customerDetails = aggregate.getMappedResults();
	return customerDetails;
}

　　Trade表：

public class TradeInfo{
	private String tid;//訂單id
	private Double payment;//支付金額
	private String buyerNick;//買家昵稱
	private String address;//地址
	private String mobile;//手機號
	private Long num;//購買商品數量
	private List<order> orders;子訂單
}

　　CustomerDetail：

public class CustomerDetail{
	private String buyerNick;//買家昵稱
	private Double totalPayment;//訂單金額
	private Integer orderNum;//訂單數
	private Integer itemNum;//商品數
	private String address;//地址
}

　　OVER!