How to run multi condition check in mongodb update query? - mongodb

Question

I have the following scenario.
I need to check multiple condition in a single update query.
Sample Data :
"host" : "zigwheels.com",
"lastAccessDate" : "20140819",
"sessionId" : "ff8378ed-ccda-4a75-b24b-4a4bb1153e39"
Here is my requirement :
obj=db.userFrequency.find({"host" : "xyz.com", "sessionId" : "ff8378ed-ccda-4a75-b24b-4a4bb1153e39"});
if(obj!=null){
if(obj.get("lastAccessDate")!= todayDate){
//If page has not visited today, increment count by 1 and update "lastAccessDate"=todayDate
db.userFrequency.update({"host" : "xyz.com","sessionId" : "ff8378ed-ccda-4a75-b24b-4a4bb1153e39"},{$set : {"lastAccessDate"=todayDate},$inc : {"count":1}});
}
else{
// If page visited today{lastAccessDate==todayDate}, no need to update count
}
}else{
//Insert the new Entry
db.userFrequency.update({"host" : "xyz.com","sessionId" : "ff8378ed-ccda-4a75-b24b-4a4bb1153e39"},{$set : {"lastAccessDate"=todayDate},$inc : {"count":1}},{upsert:true});
}
I need to do the above operation in a single query but I have GB's of data.
I tried above like below :
db.userFrequency.update({"host" : "xyz.com","lastAccessDate"!=todayDate,"sessionId" : "ff8378ed-ccda-4a75-b24b-4a4bb1153e39"},{$set : {"lastAccessDate"=todayDate},$inc : {"count":1}});
but it inserts new entry because the above condition requires three checks.
Please suggest a solution for the same.

Answer 1

It's awkward if you store your date as a string. Store dates as date type fields and this is easy:
> db.userFrequency.insert({
"host" : "zigwheels.com",
"lastAccessDate" : ISODate("2014-08-19"),
"sessionId" : "ff8378ed-ccda-4a75-b24b-4a4bb1153e39"
})
> var today = ISODate("2014-08-25")
> db.userFrequency.update({
"host" : "zigwheels.com",
"lastAccessDate" : { "$lt" : today },
"sessionId" : "ff8378ed-ccda-4a75-b24b-4a4bb1153e39"
},
{
$set : { "lastAccessDate" : today},
$inc : { "count" : 1 }
})
> db.userFrequency.findOne()
{
"_id" : ObjectId("53fbd08...398"),
"host" : "zigwheels.com",
"lastAccessDate" : ISODate("2014-08-25T00:00:00Z"),
"sessionId" : "ff8378ed-ccda-4a75-b24b-4a4bb1153e39",
"count" : 1
}
I used the $lt operator for the date test because users won't access the website from the future...hopefully. Using proper dates also surfaces another important issue- what timezone defines today? Right now, for me, it's tomorrow in Australia...