This is a sample row in my RethinkDB table.
{
"a1": "val1" ,
"a2": "val2" ,
"a3": "val3" ,
"a4": "val4" ,
"part": [
{
"id": "reql" ,
"position": "student"
} ,
{
"id": "sdsadda" ,
"position": "officer"
}
] ,
"a5": "val5"
}
I want to access a nested json object but I get the error e: Cannot perform bracket on a non-object non-sequence "string"
I need the entire row in the output for rows matching id to "reql"
This is my query
r.db('dbname').table('tablename').filter(r.row('part').contains(function(product) {
return product('id').eq("reql");
}))
This query worked before .It doesn't right now.
You'd get that error if you'd somehow ended up with an element in your part array that's a string instead of an object. Try running .filter(r.row('part').contains(function(product) { return product.typeOf().ne('OBJECT'); }), that should return all the rows that have a string in the part array.
Regarding your comment #Puja, I think this should do it for you:
r.db('dbname').table('tablename').filter(function(d){
d("part").typeOf().eq("ARRAY");
}).filter(r.row('part').contains(function(d) {
return d('id').eq("reql");
}))
Although, this is less efficient than #mlucy's answer, and you should definitely just do the one pass over your dataset to clean it up by fixing all the documents where part: STRING.
Related
I have an JSON object with the structure below. When looping over key_two I want to create a new object that I will return. The returned object should contain a title with the value from key_one's name where the id of key_one matches the current looped over node from key_two.
Both objects contain other keys that also will be included but the first step I can't figure out is how to grab data from a sibling object while looping and match it to the current value.
{
"key_one": [
{
"name": "some_cool_title",
"id": "value_one",
...
}
],
"key_two": [
{
"node": "value_one",
...
}
],
}
This is a good example of a 'join' operation (in SQL terms). JSONata supports this in a path expression. See https://docs.jsonata.org/path-operators#-context-variable-binding
So in your example, you could write:
key_one#$k1.key_two[node = $k1.id].{
"title": $k1.name
}
You can then add extra fields into the resulting object by referencing items from either of the original objects. E.g.:
key_one#$k1.key_two[node = $k1.id].{
"title": $k1.name,
"other_one": $k1.other_data,
"other_two": other_data
}
See https://try.jsonata.org/--2aRZvSL
I seem to have found a solution for this.
[key_two].$filter($$.key_one, function($v, $k){
$v.id = node
}).{"title": name ? name : id}
Gives:
[
{
"title": "value_one"
},
{
"title": "value_two"
},
{
"title": "value_three"
}
]
Leaving this here if someone have a similar issue in the future.
I am working with a sample of graphql query which I want to further bind to a FlatList object in a React-Native app. But I am still struggling to understand what I should pass on then nextToken parameter in order to get a slice of objects destined to a second page...
Tried to pass the next or last id or index, but it didn't work - it asks me to provide a valid nextToken, which I don't know what kind of data it is.
I'm running through AppSynch console.
My query:
query ListResources(
$nextTokenPlants: String = "Orange Tree"
$limitPlants: Int = 3
) {
listResources {
items {
id
name
Plants(limit: $limitPlants, nextToken:$nextTokenPlants) {
items {
id
name
filterName
description
bath
tea
insence
children
}
nextToken
}
}
nextToken
}
}
This is the result I get:
{
"data": {
"listResources": {
"items": [
{
"id": "361dee16-d567-41ed-b1d4-9baa4a7ffdcc",
"name": "Plantas",
"Plants": null
}
],
"nextToken": null
}
},
"errors": [
{
"path": [
"listResources",
"items",
0,
"Plants"
],
"data": null,
"errorType": "DynamoDB:UserIllegalArgumentException",
"errorInfo": null,
"locations": [
{
"line": 9,
"column": 7,
"sourceName": null
}
],
"message": "com.amazonaws.deepdish.common.pagination.InvalidPaginationTokenException: Invalid pagination token given."
}
]
}
I expected to get a list of 3 of the itens stored on "Plants", starting from the "Orange Tree" onwards... Could anyone pls shed some light on it?
nextToken is a String that you get in the response when you send a request, looks like
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
and it has nothing to do with your table keys.
Let me explain now how does it work:
When you send the request for the first time, you don't send nextToken since you don't have it and then you get the first portion of your data.
When you receive that first portion, if there exist more data, you get nextToken in the response.
Now, you have nextToken, you send another request to get the 2nd portion of your data. You should send that token in the request, so your backend knows from where to start.
You get your 2nd portion of data and a new nextToken if there is still some data to fetch (then you need to repeat step 2) or null in nextToken if there is no more data.
I hope that it's clear now
I am using cloudantDB and want to query a view which looks like this
function (doc) {
if(doc.name !== undefined){
emit([doc.name, doc.age], doc);
}
what should be the correct way to get a result if I have a list of names(I will be using option 'keys=[]' for it) and a range of age(for which startkey and endkey should be used)
example: I want to get persons having name "john" or "mark" or "joseph" or "santosh" and lie between age limit 20 to 30.
If i go for list of names, query should be keys=["john", ....]
and if I go for age query should use startkey and endkey
I want to do both :)
Thanks
Unfortunately, you can't do so. Using the keys parameter query the documents with the specified key. For example, you can't only send keys=["John","Mark"]&startkey=[null,20]&endkey=[{},30]. This query would only and ONLY return the document having the name John and Mark with a null age.
In your question you specified CouchDB but if you are using Cloudant, index query might be interesting for you.
You could have something like that :
{
"selector": {
"$and": [
{
"name": {
"$in":["Mark","John"]
}
},
{
"year": {
"$gt": 20,
"$lt": 30
}
}
]
},
"fields": [
"name",
"age"
]
}
As for CouchDB, you need to either separate your request (1 request for the age and 1 for the people) or you do the filtering locally.
Let's say I have this object:
{
"id": "1a48c847-4fee-4968-8cfd-5f8369c01f64" ,
"sections": [
{
"id": 0 ,
"title": "s1"
} ,
{
"id": 1 ,
"title": "s2"
} ,
{
"id": 2 ,
"title": "s3"
}
]
}
How can I directly change 2nd title "s2" to other value? without loading the object and save again? Thanks.
Update plus the changeAt term:
r.table('blog').get("1a48c847-4fee-4968-8cfd-5f8369c01f64").update(function(row){
return {
sections: row('sections').changeAt(1,
row('sections')(1).merge({title: "s2-modified"}))
}
}
The above is good if you already know the index of the item you want to change. If you need to find the index, then update it, you can use the .offsetsOf command to look up the index of the element you want:
r.table('table').get("1a48c847-4fee-4968-8cfd-5f8369c01f64").update(function(row){
return row('sections').offsetsOf(function(x){
return x('title').eq('s2')
})(0).do(function(index){
return {
sections: row('sections').changeAt(index,
row('sections')(index).merge({title: "s2-modified"}))
}
})
})
Edit: modified answer to use changeAt
I am trying to delete a nested object, but instead of disappearing it is being replaced by an empty object.
Here's the structure of my documents:
[
{
"id": "0" ,
"name": "Employee 1" ,
"schedules": [
{"Weekdays": "yes"},
{"Weekends": "no"}
]
} ,
{
"id": "1" ,
"name": "Employee 2" ,
"schedules": [
{"Weekdays": "no"},
{"Weekends": "yes"}
]
}
]
Let's say I want to delete "Weekends". Here's my code:
r.db('shank').table('teachers').replace(r.row.without({'schedules': 'Weekends'})).run(connection, function(err, result) {
if (err) throw err;
;
//confirmation stuff
});
});
Now if I look at my table, the documents have this:
"schedules": [
{"Weekdays": "yes"},
{}
]
I also tried changing it to follow the syntax described here, by making it:
r.row.without({'schedules': {'Weekends'}})
but I got an error of an unexpected token '}'. Any idea what's up?
This should work:
r.db('test').table('test').get('0').update(function(doc) {
return doc.merge({
schedules: doc("schedules").filter(function(schedule) {
return schedule.hasFields('Weekends').not()
})
})
})
The field schedules is an array, is that expected? Is there a reason why it's not just an object with two fields Weekends and Weekdays? That would make things way easier.
Your last one is close to what worked for me, just need to add a true to the nested JSON object:
r.row.without({'schedules': {'Weekends': true}})