[{isPrivate:false,message:"My name is stark",gender:"unisex",age:"19",createdBy:ObjectId("abcff9ef71fa048cea3c8a97")},{isPrivate:false,message:"My name is james",gender:"unisex",age:"20",createdBy:ObjectId("defff9ef71fa048cea3c8a97")},{isPrivate:false,message:"My name is harry",gender:"unisex",age:"20",createdBy:ObjectId("defff9ef71fa048cea3c8a97")},{isPrivate:false,message:"My name is max",gender:"unisex",age:"20",createdBy:ObjectId("abcff9ef71fa048cea3c8a97")}]

db.collection.aggregate([{$project:{isPrivate:1,message:1,gender:1,age:1,createdBy:1,matchResult:{$cond:[{$eq:["$createdBy",ObjectId("abcff9ef71fa048cea3c8a97")]},1,0]}}},{$sort:{matchResult:-1}}])