In my application, I use go 1.11 as backend. It performs CRUD operations in google datastore. I can retrieve entities from a particular kind but in an unpredictable order. I am using below datastore module:
"cloud.google.com/go/datastore"
My struct for this is:
type RuleDS struct {
Id string `json:"id" datastore:"id"`
Name string `json:"name" datastore:"name"`
Salience int `json:"salience" datastore:"salience"`
CreatedAt time.Time `json:"createdAt" datastore:"createdAt"`
}
My code to sort entities in order is as below:
var rulesDSArr []RuleDS
query := datastore.NewQuery("Rule").Order("-Salience")
_, errDS := s.DataLayer.GetAll(ctx, query, &rulesDSArr)
if errDS!= nil{
log.Errorf(ctx,"Error while getting rules : %v",errDS)
}
I also checked logs where query formed is:
&{kind:Rule ancestor:<nil> filter:[] order:[{FieldName:Salience Direction:true}] projection:[] distinct:false distinctOn:[] keysOnly:false eventual:false limit:-1 offset:0 start:[] end:[] namespace: trans:<nil> err:<nil>}
In google datastore, I have tried by making Salience property indexed as well as nonindexed but nothing worked for me. I don't know what I am doing wrong here due to which I get null as a result. If I remove .Order("-Salience") from query statement, I get all rules again.
It sounds like you don't have any values of Salience indexed. The .Order("-Salience") uses an index on the Salience value, so any entities that don't have a value for Salience indexed will not show up in the results. That said, the value in Cloud Datastore seems to be salience, so you should try .Order("-salience").
Things you can try in the cloud console:
select * from Rule order by salience descselect * from Rule order by Salience descIf neither give results then you don't have any values of Salience indexed and you'll have to rewrite your entities.