如何在java中使用$ lookup stage和spring data mongodb？

Question

直到彈簧的最後一個版本，我已經看到很多堆棧溢出問題，它顯示在spring-data-mongodb中沒有對此操作的支持。是否有任何支持此操作的新spring-data-mongodb 1.10.0

db.orders.aggregate([ 
     { 
      $lookup: 
      { 
       from: "inventory", 
       localField: "item", 
       foreignField: "sku", 
       as: "inventory_docs" 
      } 
     } 
    ]) 

Answer 1

自1.9版以來，查找支持一直存在。

LookupOperation lookupOperation = LookupOperation.newLookup(). 
            from("inventory"). 
            localField("item"). 
            foreignField("sku"). 
            as("inventory_docs"); 
Aggregation aggregation = Aggregation.newAggregation(lookupOperation); 
List<BasicDBObject> results = mongoOperations.aggregate(aggregation, "orders", BasicDBObject.class).getMappedResults();