RavenDB used to not accept Includes when the id fields were ints instead of strings.
But the documentation does not mention this limitation.
Is there any workaround that does not require changing the ids from int to strings in the .Net object model.
If you have a property that contains just the integer id of a related document, you can do this:
session.Include<User, Item>( user => user.ItemId).Load(1);
This will load users/1 and then get the value inside that user's ItemId and use the "items/" prefix to load the related item.
Related
How can I create the array of strings field type in Keystone.js 6? Array of strings isn't provided in the keystone 6 js collection of field types, does it mean that I have to use Custom Field option for my case? As far as I can tell prisma supports arrays, so there should be some way to use them in keystone 6 js.
model User {
id Int #id #default(autoincrement())
favoriteColors String[]
}
I explored keystone js 6 custom field examples, but I'm still not sure whether or not it's the solution.
I am working in a Spring, Jpa, Hibernate-Search, Lucene application. I want to index a JPA entity which has a ENUM property and use Lucene to search on that. Every element in my ENUM has a int value.
I put the #Field annotation on the property, but is not working. In the database the field is being stored as an Integer.
#Field
#Enumerated
private STATUS status = STATUS.FIRST;
Now I want to use Lucene for search using this field
//lucene query to search by that enum field
queryStatus.should(queryBuilder.keyword().onField("status").matching(1).createQuery());
I cannot change the enum storage to string type because it has other queries working and using this enum propoerty as an integer and I do not know how to index and use it.
Actually I was able to solve the issue, when searching instead of use the int value, I convert it to the explicit enum.
queryStatus.should(queryBuilder.keyword().onField("status").matching(MyClass.STATUS.fromValue(status)).createQuery());
That solved my issue.
I am looking into using Google Protobuffers for delta messaging. Meaning I only want to send out the changed values of my domain object.
But that exposes a problem with the protocol for this purpose. I can easily just omit the properties that have not changed, and that will present us with a compact message.
But what about properties that change value from _something_ to null? There is no way to distinguish between these two scenarios in a protocol buffer.
What have others done here? I am looking at a few different solutions:
Add a meta property to all objects, that is an array of int. In case any of the properties should change to null, include the field number in this array. If no properties change, then the meta property is just omitted and doesn't take up bandwidth in the message.
Add a meta property that is a bit mask, but works like the array mentioned in option 1. This might be harder for clients to understand though.
Use a standard way that I haven't been able to find yet.
BR Jay
Protobuf 3 isn't very well suited for this. But in protobuf 2, you can have a field that is present but has value of null.
Because protobuf 2 isn't going to disappear any time soon, I'd suggest just use that for this kind of purposes.
I just wanted to post a follow-up on this and explain what I did.
As #jpa correctly pointed out protobuffers are not made for delta-compression.
So the way I solved it was to use some meta properties and rely on that convention. I have a close partnership with the people consuming the data, so conventions can be agreed upon.
Values that are set specifically to null
I have added an int array to the messages. This int array is empty most of the time and does not have an impact on the message size. When a property is set to null, I will add the property tag to this array and that way indicate that it has specifically been set to null in that message update.
Arrays that are emptied
This works in the same way as the nulls array. I have added an int array to the messages. This int array is empty most of the time and does not have an impact on the message size. When an array is emptied, I will add the property tag to this array and that way indicate that it has specifically been emptied that message update.
Objects that are deleted
To indicate that an object has been deleted, I have added a boolean property indicating that the object has been deleted. When the object is deleted I will set this value to true, and otherwise null, so it doesn't take up space in the message. The resulting message is the key identifier for that object and the boolean indicating that it is deleted.
It requires that the convention is understood by the clients but otherwise it works pretty well.
I use the graph version of OrientDB. Now I created a schema-less class, where I want to index a variable. This variable needs to become a property first. But when I try to create this property - of type string (or binary, or whatever) - it responds:
com.orientechnologies.orient.core.exception.OSchemaException: The database contains some schema-less data in the property 'clazz.clazz_name' that is not compatible with the type STRING. Fix those records and change the schema again [ONetworkProtocolHttpDb]
So I need to fix something, but what? What characters are illegal for a variable to become a property so that it can be indexed? (BTW, lists are also not an option)
There was indeed a problem I created.
I created a super-class where the property had to be created. One of the sub-classes inserted a List instead of a String. So when querying all vertices of sub-type
final Iterable<Vertex> iterable = this.graph.getVerticesOfClass("clazz");
I printed all types of clazz_name by vertex.getProperty("clazz_name").getClass().getName() where I saw OLinkedList. Reinserting those vertices fixed my problem.
All the examples I am finding for using the AliasToBean transformer use the sessions CreateSqlQuery method rather than the CreateQuery method. They also only return the basic value types, and not any object's of the existing mapped types.
I was hoping it would be possible that my DTO have a property of one of my mapped Domain objects, like below, but I am not getting traction. I get the following exception:
Could not find a setter for property '0' in class 'namespace.DtoClass'
My select looks like the following on my mapped classes (I have confirmed the mappings pull correctly):
SELECT
fcs.MeasurementPoint,
fcs.Form,
fcs.MeasurementPoint.IsUnscheduled as ""IsVisitUnscheduled"",
fcs.MultipleEntryAllowed
FROM FormCollectionSchedule fcs
My end query will be more complex, but I wanted to confirm if this AliasToBean method can return mapped domain objects as well as basic field values from tables retrieved via sql.
the query execution looks like the following:
var result = session.CreateQuery(hqlQuery.ToString())
.SetResultTransformer(NHibernate.Transform.Transformers.AliasToBean(typeof (VisitFormCollectionResult)))
.List<VisitFormCollectionResult>();
note: the VisitFormCollectionResult DTO has more properties, but I wanted to know if I could populate the domain object properties matching the names
update found my problem! I have to explicitly alias each of the fields. once I added an alias, even though the member property on the class matched my DTO's property name, the hydration of the object worked correctly.
The answer to my own question was that each of the individual fields in the select needed an explicit alias matching the property, regardless if the field name already matched the property name of the DTO object:
SELECT
fcs.MeasurementPoint as "MeasurementPoint",
fcs.Form as "Form",
fcs.MeasurementPoint.IsUnscheduled as "IsVisitUnscheduled",
fcs.MultipleEntryAllowed as "MultipleEntryAllowed"
FROM FormCollectionSchedule fcs