How is a field name that is a reserved keyword able to be 'escaped' to be used in a type?
type User = {
type: Text; // `type` cant be used since its reserved
};
I want to be able to return data with a field name of type.
Is there a character prefix or something so that when it serialized in a request it outputs 'type'?
Either that or some sort of serialization decoration for the field to specify 'type'
From the docs:
If the field name is a reserved name in Motoko, an undescore is appended. So record { if : bool } corresponds to { if_ : Bool }.
Related
I'm using mikro-orm for db related opeartions. My db entity has a number field:
#Property({ defaultRaw: 'srNumber', type: 'number' })
srNumber!: number;
and corresponding db column (Postgresql) is:
srNumber(int8)
The query input for where param in mikro-orm EntityRepository's findAndCount(where, option) is:
repository.findAndCount({"srNumber":{"$like":"%1000%"}}, options)
It translates to:
select * from table1 where srNumber like '%1000%'
The problem here is since srNumber column is not a string, there is a type-mismatch and query fails. Casting it like CAST(srNumber AS TEXT) like '%1000%' should work in db.
Is there any way to somehow specify the field casting here?
You can use custom SQL fragments in the query. To get around strictly typed FilterQuery, you can use expr which is just an identity function (returns its parameter), so have effect only for TS checks.
Something like this should work:
import { expr } from '#mikro-orm/core';
const res = await repo.findAndCount({
[expr('cast(srNumber as text)')]: { $like: '%1000%' },
}, options);
https://mikro-orm.io/docs/entity-manager/#using-custom-sql-fragments
FaunaDB's documentation covers how to update a document, but their example assumes that I'll have the id to pass into Ref:
Ref(schema_ref, id)
client.query(
q.Update(
q.Ref(q.Collection('posts'), '192903209792046592'),
{ data: { text: "Example" },
)
)
However, I'm wondering if it's possible to update a document without knowing its id. For instance, if I have a collection of users, can I find a user by their email, and then update their record? I've tried this, but Fauna returns a 400 (Database Ref expected, String provided):
client
.query(
q.Update(
q.Match(
q.Index("users_by_email", "me#example.com")
),
{ name: "Em" }
)
)
Although Bens comments are correct, (that's the way you do it), I wanted to note that the error you are receiving is because you are missing a bracket here: "users_by_email"), "me#example.com"
The error is logical if you know that Index takes an optional database reference as second argument.
To clarify what Ben said:
If you do this you'll get another error:
Update(
Match(
Index("accounts_by_email"), "test#test.com"
),
{ data: { email: "test2#test.com"} }
)
Since Match could potentially return more then one element. It returns a set of references called a SetRef. Think of setrefs as lists that are not materialized yet. If you are certain there is only one match for that e-mail (e.g. if you set a uniqueness constraint) you can materialize it using Paginate or Get:
Get:
Update(
Select(['ref'], Get(Match(
Index("accounts_by_email"), "test#test.com"
))),
{ data: { email: 'test2#test.com'} }
)
The Get returns the complete document, we need to specify that we require the ref with Select(['ref']..
Paginate:
Update(
Select(['data', 0],
Paginate(Match(
Index("accounts_by_email"), "test#test.com"
))
),
{ data: { email: "testchanged#test.com"} }
)
You are very close! Update does require a ref. You can get one via your index though. Assuming your index has a default values setting (i.e. paging a match returns a page of refs) and you are confident that the there is a single match or the first match is the one you want then you can do Select(["ref"], Get(Match(Index("users_by_email"), "me#example.com"))) to transform your set ref to a document ref. This can then be passed into update (or to any other function that wants a document ref, like Delete).
I have this GraphQL query:
{
timeline(limit:10){
eventType
level: eventSeverity
},
}
I would like to set the 'eventSeverity' alias name using a variable, rather than the fixed name 'level'. Something like this:
query($name:String!)
{
timeline(limit:10){
eventType
$name: eventSeverity
},
}
But running the above yields this error:
Syntax Error GraphQL request (5:5) Expected Name, found $
Is it possible to use a variable value as an alias name at all?
You cannot use dynamic field name in GraphQL, but what you can do is create a field that accepts a name argument, example
query($name: String!) {
timeline(limit: 10) {
eventType
eventSeverity(name: $name) // Write a resolve function that returns timeline[name]
}
}
I have a problem when querying mongoDB with nested objects notation:
db.messages.find( { headers : { From: "reservations#marriott.com" } } ).count()
0
db.messages.find( { 'headers.From': "reservations#marriott.com" } ).count()
5
I can't see what I am doing wrong. I am expecting nested object notation to return the same result as the dot notation query. Where am I wrong?
db.messages.find( { headers : { From: "reservations#marriott.com" } } )
This queries for documents where headers equals { From: ... }, i.e. contains no other fields.
db.messages.find( { 'headers.From': "reservations#marriott.com" } )
This only looks at the headers.From field, not affected by other fields contained in, or missing from, headers.
Dot-notation docs
Since there is a lot of confusion about queries MongoDB collection with sub-documents, I thought its worth to explain the above answers with examples:
First I have inserted only two objects in the collection namely: message as:
> db.messages.find().pretty()
{
"_id" : ObjectId("5cce8e417d2e7b3fe9c93c32"),
"headers" : {
"From" : "reservations#marriott.com"
}
}
{
"_id" : ObjectId("5cce8eb97d2e7b3fe9c93c33"),
"headers" : {
"From" : "reservations#marriott.com",
"To" : "kprasad.iitd#gmail.com"
}
}
>
So what is the result of query: db.messages.find({headers: {From: "reservations#marriott.com"} }).count()
It should be one because these queries for documents where headers equal to the object {From: "reservations#marriott.com"}, only i.e. contains no other fields or we should specify the entire sub-document as the value of a field.
So as per the answer from #Edmondo1984
Equality matches within sub-documents select documents if the subdocument matches exactly the specified sub-document, including the field order.
From the above statements, what is the below query result should be?
> db.messages.find({headers: {To: "kprasad.iitd#gmail.com", From: "reservations#marriott.com"} }).count()
0
And what if we will change the order of From and To i.e same as sub-documents of second documents?
> db.messages.find({headers: {From: "reservations#marriott.com", To: "kprasad.iitd#gmail.com"} }).count()
1
so, it matches exactly the specified sub-document, including the field order.
For using dot operator, I think it is very clear for every one. Let's see the result of below query:
> db.messages.find( { 'headers.From': "reservations#marriott.com" } ).count()
2
I hope these explanations with the above example will make someone more clarity on find query with sub-documents.
The two query mechanism work in different ways, as suggested in the docs at the section Subdocuments:
When the field holds an embedded document (i.e, subdocument), you can either specify the entire subdocument as the value of a field, or “reach into” the subdocument using dot notation, to specify values for individual fields in the subdocument:
Equality matches within subdocuments select documents if the subdocument matches exactly the specified subdocument, including the field order.
In the following example, the query matches all documents where the value of the field producer is a subdocument that contains only the field company with the value 'ABC123' and the field address with the value '123 Street', in the exact order:
db.inventory.find( {
producer: {
company: 'ABC123',
address: '123 Street'
}
});
I have a javastack trace in message field and an array field having list of string like ["NullPointer", "TimeOutException"].
I want a conditional check on message field such that it checks if message contains any of from list of string.
Any idea how to get this?
It's a bit of a hack, but check out the translate{} filter. You could define your fields to translate to "1" (true, etc), with a default of "0". Then check that value to determine if it was in the set.
EDIT: for those who don't like to fish:
filter {
translate {
field => myInputField
dictionary => [
"NullPointer", 1,
"TimeOutException", 1
]
fallback => 0
destination => myOutputField
}
if [myOutputField] == "1" {
# it contained one of the items in the dictionary
...
}
else {
# it did not contain one of the items in the dictionary
...
}
}