ios - How to Rectify the Relationship Fault in CoreData While parsing RESTKIT? -

i want store ey_connectionusage entity value ey_connection entity cell.i have added 2 entities attributes , created relationship name usagedata.but shows error "<'usagedata' relationship fault>".this method wrote map restkit value coredata.

dataaccesshandler.m

+(void)createconnectionmappingwithstore:(rkmanagedobjectstore *)managedobjectstore saveindelegate:(appdelegate *)appdelegate{  nslog(@"appdele==>>%@",appdelegate); rkentitymapping *connectionmapping = [rkentitymapping mappingforentityforname:@"ey_connections" inmanagedobjectstore:managedobjectstore]; connectionmapping.identificationattributes = @[@"connectionnumber"]; [connectionmapping addattributemappingsfromdictionary:@{ @"serviceno" : @"connectionservicenumber", @"name" : @"connectionname", @"region" : @"connectionregion", @"phase" : @"connectionphase",     @"circle" : @"connectioncircle", @"section" : @"connectionsection", @"load" : @"connectionload",     @"distribution" : @"connectiondistribution", @"meterno" : @"connectionmeternumber", @"connectionnumber" : @"connectionnumber", @"address" : @"connectionaddress", @"servicestatus" : @"connectionstatus"}];    rkentitymapping *connectionusagemapping = [rkentitymapping mappingforentityforname:@"ey_connectionusage" inmanagedobjectstore:managedobjectstore]; connectionusagemapping.identificationattributes = @[@"usageassessmentdate"]; [connectionusagemapping addattributemappingsfromdictionary:@{ @"assessment_date" : @"usageassessmentdate", @"reading" : @"usagereading", @"units" : @"usageunits", @"amount" : @"usageamount",                                                          @"payment_date" : @"usagepaymentdate", @"status" : @"usagestatus"}];  [connectionmapping addpropertymapping:[rkrelationshipmapping relationshipmappingfromkeypath:@"usage" tokeypath:@"usagedata" withmapping:connectionusagemapping]];  rkresponsedescriptor *articlelistresponsedescriptor = [rkresponsedescriptor responsedescriptorwithmapping:connectionmapping                                              method:rkrequestmethodget                                         pathpattern:@"user_history/consumer/data.json"                                             keypath:nil                                         statuscodes:rkstatuscodeindexsetforclass(rkstatuscodeclasssuccessful)  ];  [appdelegate createobjectmanagerforurl:@"http://sciflare.com/energyly/api/" andaddresponsedescriptor:articlelistresponsedescriptor]; [afnetworkactivityindicatormanager sharedmanager].enabled = yes;  } 

<'usagedata' relationship fault>

this means relationship data hasn't been loaded yet, because haven't tried use it. logging object isn't enough load data. whole point of faulting system prevent data being loaded memory @ same time.

so, basically, isn't problem it's fault. when try use data populated , fine.