Mongo db readingdocumentusecases

Mongo db readingdocumentusecases

• 1.
  MongoDB Reading/finding Document Reading/finding DocumentUse Case detailed
• 2.
  Reading/finding in Document Syntax db.collection.find(<query>, <projection> ) <query> argument corresponds to the WHERE statement, and <projection> argument corresponds to the list of fields to select from the result set.
• 3.
  findOne() Find the firstrecord in the document > db.user.findOne() { "_id" : ObjectId("513c6ef1cfce9090d3fd8b1d"), "date" : ISODate("2013-03-10T11:30:50.555Z"), "remarks" : [ { "name" : "anish", "rate" : "good" }, { "name" : "nath", "rate" : "bad" } ], "uName" : "anish" }
• 4.
  findOne() : specifywhich key to return • Find the first record in the document and return only “_id” > db.user.findOne({},{"_id":1}) { "_id" : ObjectId("513c6ef1cfce9090d3fd8b1d") } • Find the first record in the document and return only “_id” and date > db.user.findOne({},{"_id":1,"date":1}) { "_id" : ObjectId("513c6ef1cfce9090d3fd8b1d"), "date" : ISODate("2013-03-10T11:30:50.555Z") } • Find the first record in the document and return all the data except the “_id” field > db.user.findOne({},{"_id":0}) { "date" : ISODate("2013-03-10T11:30:50.555Z"), "remarks" : [ { "name" : "anish", "rate" : "good" }, { "name" : "nath", "rate" : "bad" } ], "uName" : "anish" }
• 5.
  finding in Subdocument >db.user.find( {"remarks.name":"anish"}) { "_id" : ObjectId("513c6ef1cfce9090d3fd8b1d"), "date" : ISODate("2013-03- 10T11:30:50.555Z"), "remarks" : [ { "name " : "anish", "rate" : "good" }, { "name" : "nath", "rate" : "bad" } ], "uName" : "anish" }
• 6.
  findOne()/find() • Summary on<K,boolean> specify <“k”,0> or <“K”,1> to show/hide data to be returned from the collection
• 7.
  Thanks for Watching feedback appreciated……………… …………