node.js - Compare two date fields in MongoDB -

in collection each document has 2 dates, modified , sync. find modified > sync, or sync not exist.

i tried

{'modified': { $gt : 'sync' }} 

but it's not showing expected. ideas?

thanks

you can not compare field value of field normal query matching. however, can aggregation framework:

db.so.aggregate( [     { $match: …your normal other query… },     { $match: { $eq: [ '$modified', '$sync' ] } } ] ); 

i put …your normal other query… in there can make bit use index. if want documents name field charles can do:

db.so.ensureindex( { name: 1 } ); db.so.aggregate( [     { $match: { name: 'charles' } },     { $project: {          modified: 1,          sync: 1,         name: 1,         eq: { $cond: [ { $gt: [ '$modified', '$sync' ] }, 1, 0 ] }      } },     { $match: { eq: 1 } } ] ); 

with input:

{ "_id" : objectid("520276459bf0f0f3a6e4589c"), "modified" : 73845345, "sync" : 73234 } { "_id" : objectid("5202764f9bf0f0f3a6e4589d"), "modified" : 4, "sync" : 4 } { "_id" : objectid("5202765b9bf0f0f3a6e4589e"), "modified" : 4, "sync" : 4, "name" : "charles" } { "_id" : objectid("5202765e9bf0f0f3a6e4589f"), "modified" : 4, "sync" : 45, "name" : "charles" } { "_id" : objectid("520276949bf0f0f3a6e458a1"), "modified" : 46, "sync" : 45, "name" : "charles" } 

this returns:

{     "result" : [         {             "_id" : objectid("520276949bf0f0f3a6e458a1"),             "modified" : 46,             "sync" : 45,             "name" : "charles",             "eq" : 1         }     ],     "ok" : 1 } 

if want more fields, need add them in $project.