javascript - How to match a document with the value of an object attribute in Mongodb -

-

i'm trying match document in mongodb:

my document model :

profile: {   languages: [     {"name": "french", "level": 1},     {"name": "english", "level": 2},     {"name": "spanish", "level": 4}   ] }

what (can) have search result set:

lang = ["french", "english"]; objlang = [   {name: "french"},   {name: "english"} ];

what need db.find() documents match @ least 1 of languages, example :

profile.languages.name = "french"

or

profile.languages.name = "english"

what mean if have french or english in option set, need users have element of languages array name match 1 of options, no matter level of languages.

so, unless i'm wrong, can't 

db.find({"profile.languages": {$in: [{name: "french"}, {name: "english"}]});

how proceed ?

thanks lot.

david

actually, right:

db.collection.find({"profile.languages.name":{$in: ["french","english"]} })

since profile.languages array of subdocuments, can call in 1 of subdocument's keys , subsequent query gets mapped subdocuments containing key.

however, without proper indexing, added .explain() shows pretty ugly:

{   "queryplanner" : {     "plannerversion" : 1,     "namespace" : "test.languages",     "indexfilterset" : false,     "parsedquery" : {         "profile.languages.name" : {             "$in" : [                 "english",                 "french"             ]         }     },     "winningplan" : {         "stage" : "collscan",         "filter" : {             "profile.languages.name" : {                 "$in" : [                     "english",                     "french"                 ]             }         },         "direction" : "forward"     },     "rejectedplans" : [ ]   } }

(serverinfowas ommited).

so in order make query efficient, need create index on field want query:

db.languages.ensureindex({"profile.languages.name":1})

an added explain tells matching documents identified via index: 

{ "queryplanner" : {     "plannerversion" : 1,     "namespace" : "test.languages",     "indexfilterset" : false,     "parsedquery" : {         "profile.languages.name" : {             "$in" : [                 "english",                 "french"             ]         }     },     "winningplan" : {         "stage" : "fetch",         "inputstage" : {             "stage" : "ixscan",             "keypattern" : {                 "profile.languages.name" : 1             },             "indexname" : "profile.languages.name_1",             "ismultikey" : true,             "direction" : "forward",             "indexbounds" : {                 "profile.languages.name" : [                     "[\"english\", \"english\"]",                     "[\"french\", \"french\"]"                 ]             }         }     },     "rejectedplans" : [ ]   },   "ok" : 1 }

Comments

Post a Comment

Popular posts from this blog

qt - Using float or double for own QML classes -

-
i've created components , helper methods using c++ , qt used in qml gui. of methods calculate gui elements (size, transformations, scene graph items creation). target arm 32 bit using opengl / eglfs render output. opengl using float , qml using real (defined double ). what should use in c++ do not lose precision? if use qreal ( double ) shouldn't lose precision. if git grep float in qtbase.git , can find out bit more: dist/changes-5.2.0-**************************************************************************** dist/changes-5.2.0-* important behavior changes * dist/changes-5.2.0-**************************************************************************** dist/changes-5.2.0- dist/changes-5.2.0- - qt compiled qreal typedef'ed double on dist/changes-5.2.0: platforms. qreal float on arm chipsets before. guarantees more dist/changes-5.2.0- consistent behavior between platforms qt supports, binary dist/chan...
Read more

Create Outlook appointment via C# .Net -

-
i need create outlook appointment using microsoft.office.interop.outlook , while can work locally on own workstation , works if run web application via server's browser, not work when connect server externally. hence, think might permission issue. i changed application pool identity " localsystem " don't access denied error. unfortunately, doesn't work. the app behaves if appointment created, appointment doesn't appear in outlook. here include file on top of aspx.cs page using outlook = microsoft.office.interop.outlook; here code using pop appointment. outlook.application apptapp = new outlook.application(); outlook.appointmentitem appt = apptapp.createitem(outlook.olitemtype.olappointmentitem) outlook.appointmentitem; appt.subject = txtfirstname.text + " " + txtlastname.text; appt.body = txtcomment.text; appt.alldayevent = false; appt.start = datetime.parse(txtreminderdate.text + " 8:00 am"); appt.end = datetime.p...
Read more

ios - Swift Array Resetting Itself -

-
i have 2 arrays: pointhistory , datehistory . have nstimer , , when timer runs out, action called. in action appending int pointhistory , , current date string datehistory . here timer action: func timeraction() { let steppervalue = int(stepper.value) employee.numberofpoints = steppervalue networking.saveemployee(employee, completion: { (error) -> void in if error != nil { let alert = uialertcontroller(title: "error", message: "there error updating \(self.employee.name)'s points", preferredstyle: .alert) let alertaction = uialertaction(title: "ok", style: .cancel, handler: nil) alert.addaction(alertaction) self.presentviewcontroller(alert, animated: true, completion: nil) } }) var dateformatter = nsdateformatter() dateformatter.dateformat = "mm-dd-yyyy" dateformatter.timezone = nstimezone.localtimezone() var date = nsdate() var ...
Read more