I've been struggling to get used to Merge
of gorethink
(RethinkDB's driver in Go)
result,err:=r.Table("quote").GetAllByIndex("idUser",idUser).
OrderBy(r.Desc("created_at")).Merge(func(row r.Term) interface{}{
res,_:=r.Table("article").Get(row.Field("idArticle")).Run(session)
// TODO
return map[string]interface{}{
// TODO
}
}).Run(session)
I have 3 collections: article
, quote
, and user
With the above function I intend to:
In JavaScript API for RethinkDB, I implemented like this:
findAllByUser = function(idU){
return r.table(table)
.filter({idUser: idU})
.orderBy(r.desc('created_at'))
.merge(function(quote){
var article = r.table('article').get(quote('idArticle'));
return {
tags: {keywords: article('keywords')}
}
})
.run(connection)
.then(function(result){
return result.toArray();
});
}
But I still haven't managed to do the same in gorethink. How can I get the value of Term
row.Field("idArticle")
and use it for later queries and Merge
?
Thank you very much. I managed to solve the panicking error
True answer is:
result,err:=r.Table("quote").Filter(r.Row.Field("idUser").Eq(idUser)).
OrderBy(r.Desc("created_at")).
Merge(func(quote r.Term) interface{}{
fmt.Println(quote.Field("idArticle"))
article:=r.Table("article").Get(quote.Field("idArticle"))
return map[string]interface{}{
"tags":map[string]interface{}{
"keywords":article.Field("keywords"),
},
}
}).
Run(config.Connection())
I got panicked because of last night's statement of returned address for cursor result: It was: var all map[string]interface{}
While it should be: var all []interface{}
Then it panicked in err=result.All(&all)
Copied my answer from https://github.com/dancannon/gorethink/issues/291
You should be able to convert your JS query to Go by using the subquery without calling Run
. For example:
r.Table(table)
.Filter(map[string]interface{}{"idUser": idU})
.OrderBy(r.Desc("created_at"))
.Merge(func(quote r.Term){
article := r.Table("article").Get(quote.Field("idArticle"))
return map[string]interface{}{
"tags": map[string]interface{}{
"keywords": article("keywords"),
},
}
})