$片的MongoDB的Java

Question

我怎樣才能讓這個查詢在Java中

db.comments.find({ "hsID.$id" { "$oid" : "4fe71a50e7e9f22ae5fb96bf"}} , {commentList: { $slice : [ 2 , 2]}}); 

此代碼我做

BasicDBObject query = new BasicDBObject(); 
     BasicDBObject allFields = new BasicDBObject(); 
     ObjectId objectId = new ObjectId(objId); 
     query.put("{hsID.$id", objectId); 
     Integer[] sliceInt = { startIndex, pageSize }; 
     query.put( 
       "commentList", 
       new BasicDBObject().append("$slice", sliceInt)); 
DBCursor resultsCursor = CommentColl.find(allFields,query); 

和輸出

，輸出是

query = { "{hsID.$id" : { "$oid" : "4fe71a50e7e9f22ae5fb96bf"} , "commentList" : { "$slice" : [ 2 , 2]}} 

感謝您的幫助

Answer 1

您需要將查詢與要返回的字段分開。嘗試更多的東西是這樣的：

BasicDBObject query = new BasicDBObject("hsID.$id", new ObjectId(objId)); 
BasicDBObject fields = new BasicDBObject(
     "commentList", 
     new BasicDBObject("$slice", new int[] { startIndex, pageSize })); 
DBCursor resultsCursor = CommentColl.find(query, fields); 

還請注意，我刪除你已HSID的$ id前的大括號。