In my DocumentDb documents, I don't want to include properties with NULL values. For example, I have the following POCO class.
public class Person
{
[JsonProperty(PropertyName="id")]
public int PersonId {get; set;}
[JsonProperty(PropertyName="firstName")]
public string FirstName {get; set;}
[JsonProperty(PropertyName="middleName")]
public string MiddleName {get; set;}
[JsonProperty(PropertyName="lastName")]
public string LastName {get; set;}
}
Some people don't have middle names and when I save a person's document in my collection, I don't want the middle name to be included. Currently, a person without a middle name is saved as:
{
"id": 1234,
"firstName": "John",
"middleName": null,
"lastName": "Smith"
}
Is this normal behavior? If not, how do I NOT include the middle name property with a NULL value in my document?
P.S. All serialization/deserialization is handled by JSON.NET
You can do that when you initialize the Cosmos Client, there's a serialization option which is similar to the JSON.Net.
CosmosClient client = new CosmosClient(yourConnectionString, new CosmosClientOptions()
{
SerializerOptions = new CosmosSerializationOptions()
{
IgnoreNullValues = true,
}
});
I think I found the answer. Looks like I can tell JSON.NET to ignore properties with NULL values using
NullValueHandling = NullValueHandling.Ignore
Here's the documentation:
http://james.newtonking.com/archive/2009/10/23/efficient-json-with-json-net-reducing-serialized-json-size
Related
We have below entity inherited from tableEntity
public class LinkEntity : TableEntity
{
public string LinkKey {get; set;}
public string LinkName {get; set;}
public int LinkValue {get; set;}
public string LinkId {get {return PartitionKey;} set;}
public LinkEntity(Link link)
{
PartitionKey = link.LinkId;
RowKey = link.LinkKey;
LinkValue = link.Value;
LinkName = link.LinkName;
}
}
I have an API that adds the above entity using Post and below steps:
linkValue of Link is null.
var cloudTable = cloudTableClient.GetTableReference(LinkTable);
cloudTable.CreateIfNotExistsAsync();
var postOperation = TableOperation.Insert(LinkEntity(link));
cloudTable.ExecuteAsync(postOperation);
But, when I do get on above, I again receive linkValue as null.
Hence, I don't want to add this value in tableStorage or column/property for entity when this value is null.
I cannot get rid of property linkValue completely because it is being used by other API which is a required field over there. Hence, any advise would be appreciated.
I think there should be some way where we can add required fields and ignore or remove columns completely from entities since tables in table storage is schemaless.
TL;DR;
Please make the LinkValue property nullable. That should solve the problem. So your entity definition would be:
public class LinkEntity : TableEntity
{
public string LinkKey {get; set;}
public string LinkName {get; set;}
public int? LinkValue {get; set;}
public string LinkId {get {return PartitionKey;} set;}
public LinkEntity(Link link)
{
PartitionKey = link.LinkId;
RowKey = link.LinkKey;
LinkValue = link.Value;
LinkName = link.LinkName;
}
}
Longer Version (Somewhat) :)
As you rightly mentioned, Azure Tables are schema less. Another important thing to understand is that there's no concept of null values in an entity in Azure Tables. Either an attribute is present in an entity or it is not.
By keeping int as the data type (which has a default value of 0) for your LinkValue attribute, even if you don't provide any value, this attribute will be initialized with default value and that gets stored.
By making the data type as nullable int, if you don't provide any value for this attribute, it won't get initialized and will be ignored by the SDK when the entity gets serialized.
However you will need to ensure that the application which consumes this entity (i.e. the receiving end) does not assume that the value will always be present in this attribute and should be prepared to handle null values.
I have a table called PODetail with a primary Key of POno and ItemCode and I have the following:
[Route("/podetail/{POno}/{ItemCode}")]
public class UpdatePODetail : IReturn<PODetail> {
public string POno { get; set; }
public string ItemCode { get; set; }
public int ? QtyPend { get; set; }
public decimal ? NewPrice { get; set; }
public bool ? BackOrder { get; set; }
public string ActionCode { get; set; }
public bool ? OpenOrder { get; set; }
}
public class PODetailService : Service {
public object Any(UpdatePODetail request) {
var podetail = Db.SingleFmt<PODetail>("ItemCode = {0} AND POno = {1}", request.ItemCode, request.POno);
// var cap = new CaptureSqlFilter();
try {
Db.Update(podetail);
} catch {
// var sql = string.Join(";\n\n", cap.SqlStatements.ToArray());
}
:
:
try {
Db.Update(podetail);
} catch (Exception ex) {
string error = ex.Message;
}
return podetail;
}
}
I added the Db.Update call at the top just to check to see if there was some issue changing a column, but I get
Violation of PRIMARY KEY constraint 'aaaaaPoDetail_PK'. Cannot insert
duplicate key in object 'dbo.PODetail'.
So then I added the cap = line to see the SQL code which returns
UPDATE "PODetail" SET "NewItemCode"=#NewItemCode, "POno"=#POno, "Vendor"=#Vendor, "ActionCode"=#ActionCode, "Price"=#Price, "NewPrice"=#NewPrice, "CostPrice"=#CostPrice, "QtyOrd"=#QtyOrd, "QtyRcv"=#QtyRcv, "QtySPO"=#QtySPO, "QtyPend"=#QtyPend, "BackOrder"=#BackOrder, "OpenOrder"=#OpenOrder, "OrderDate"=#OrderDate, "InvoiceNo"=#InvoiceNo, "InvoiceVendor"=#InvoiceVendor, "InvoiceDate"=#InvoiceDate, "InvoiceDiscount"=#InvoiceDiscount, "QtyCancel"=#QtyCancel, "Qtylabels"=#Qtylabels, "REOVendor"=#REOVendor, "CurrentRcvQty"=#CurrentRcvQty, "SOPickQty"=#SOPickQty, "SOItem"=#SOItem, "QtyOther"=#QtyOther, "BackOrderCode"=#BackOrderCode WHERE "ItemCode"=#ItemCode
And then it runs fine uncommented -- no exceptions .. if I remove it it gets the Primary Key error
What is the deal -- why do I need that CaptureSqlFilter call -- or what I do I need to change so that it knows both PoNo and ItemCode are primary Keys or the update needs to say WHERE "ItemCode"=#ItemCode AND "POno"=#PONo? It almost seems as if it is trying to do an INSERT vs an UPDATE without the CaptureSqlFilter
Update 1
The documentation said :
Limitations For simplicity, and to be able to have the same POCO class
persisted in db4o, memcached, redis or on the filesystem (i.e.
providers included in ServiceStack), each model must have a single
primary key, by convention OrmLite expects it to be Id although you
use [Alias("DbFieldName")] attribute it map it to a column with a
different name or use the [PrimaryKey] attribute to tell OrmLite to
use a different property for the primary key.
You can still SELECT from these tables, you will just be unable to
make use of APIs that rely on it, e.g. Update or Delete where the
filter is implied (i.e. not specified), all the APIs that end with
ById, etc.
Workaround single Primary Key limitation
A potential workaround to support tables with multiple primary keys is
to create an auto generated Id property that returns a unique value
based on all the primary key fields,
So I tried to add this
public class PODetail {
public string Id { get { return this.ItemCode + "/" + this.POno; } }
public string ItemCode { get; set; }
public string NewItemCode { get; set; }
public string POno { get; set; }
:
}
But when it went to execute :
Db.SingleFmt<PODetail>
It error out with ID not a valid column or column not found or something like that
So I then tried
public class PODetail {
//public string Id { get { return this.ItemCode + "/" + this.POno; } }
[PrimaryKey]
public string ItemCode { get; set; }
public string NewItemCode { get; set; }
[PrimaryKey]
public string POno { get; set; }
:
}
and it worked on the Db.SingleFmt ... and the Db.Update
So then I added back in the CaptureSqlFilter to see what the query looked like and I got
UPDATE "PODetail" SET "NewItemCode"=#NewItemCode, "Vendor"=#Vendor, "ActionCode"=#ActionCode, "Price"=#Price, "NewPrice"=#NewPrice, "CostPrice"=#CostPrice, "QtyOrd"=#QtyOrd, "QtyRcv"=#QtyRcv, "QtySPO"=#QtySPO, "QtyPend"=#QtyPend, "BackOrder"=#BackOrder, "OpenOrder"=#OpenOrder, "OrderDate"=#OrderDate, "InvoiceNo"=#InvoiceNo, "InvoiceVendor"=#InvoiceVendor, "InvoiceDate"=#InvoiceDate, "InvoiceDiscount"=#InvoiceDiscount, "QtyCancel"=#QtyCancel, "Qtylabels"=#Qtylabels, "REOVendor"=#REOVendor, "CurrentRcvQty"=#CurrentRcvQty, "SOPickQty"=#SOPickQty, "SOItem"=#SOItem, "QtyOther"=#QtyOther, "BackOrderCode"=#BackOrderCode WHERE "ItemCode"=#ItemCode AND "POno"=#POno
Which is what I wanted in the first place.
It works but what is the deal can you have the [PrimaryKey] attribute multiple times (it appears so) and also then why didn't the autogenerated Id work? Just wondering if I am missing something or not understanding the documentation correctly.
Oh and sorry for posting in the comments!
what I do I need to change so that it knows both PoNo and ItemCode are
primary Keys
OrmLite's primary limitation is that each Table has a single primary Key.
Also you can use the built-in Profiling or debug logging to view the generated SQL without needing to change code to use CaptureSqlFilter.
I'd also recommend that you don't use the Request DTO for anything other than defining your Service with. You can use the built-in AutoMapping to easily use it to populate your data model.
I am a .Net developer and is currently exploring on ArangoDB. I have played around with the arangod web user interface and arangod and like this NoSql very much until I delve into the detail of coding. I could not find the .Net driver working properly. Even for simple CRUD operation. Here's the problem.
ArangoClient.AddConnection("127.0.0.1", 8529, false, "Sample", "Sample");
var db = new ArangoDatabase("Sample");
string collectionName = "MyTestCollection";
var collection = new ArangoCollection();
collection.Name = collectionName;
collection.Type = ArangoCollectionType.Document;
if (db.Collection.Get(collectionName) == null)
{
db.Collection.Create(collection);
}
var employee = new Employee();
employee.Id = "1234";
employee.Name = "My Name";
employee.Salary = 33333;
employee.DateOfBirth = new DateTime(1979, 7, 22);
db.Document.Create<Employee>("MyTestCollection", employee);
employee.Name = "Tan";
db.Document.Update(employee);
It thrown the error for db.Document.Update(employee). Here's the error message: Field '_id' does not exist.
Then I tried to add the field _id though I think it is weird, it prompted me another error message.
Arango.Client.ArangoException : ArangoDB responded with error code BadRequest:
expecting PATCH /_api/document/<document-handle> [error number 400]
at Arango.Client.Protocol.DocumentOperation.Patch(Document document, Boolean waitForSync, String revision)
at Arango.Client.ArangoDocumentOperation.Update[T](T genericObject, Boolean waitForSync, String revision) ...
I have no clues at all and do not know how to to proceed further. Any help will be much appreciated. Thanks.
This is likely due to the definition of the Employee class, which is not contained in the above snippet.
To identify a document in a collection, documents have special system attributes, such as _id, _key and _rev. These attributes should be mapped to properties in .NET classes, even if not used explicitly. So one property in the class should be tagged with "Identity", one with "Key", and one with "Revision". Here is an example class definition that should work:
public class Employee
{
/* this will map the _id attribute from the database to ThisIsId property */
[ArangoProperty(Identity = true)]
public string ThisIsId { get; set; }
/* this will map the _key attribute from the database to the Id property */
[ArangoProperty(Key = true)]
public string Id { get; set; }
/* here is _rev */
[ArangoProperty(Revision = true)]
public string ThisIsRevision { get; set; }
public DateTime DateOfBirth { get; set; }
public string Name { get; set; }
public int Salary { get; set; }
public Employee()
{
}
}
The ThisIsId property will contain the automatically assigned _id value, and can also be used to retrieve the document easily later:
var employeeFromDatabase = db.Document.Get<Employee>(employee.ThisIsId);
You can of course rename the properties to your like.
I was learning AutoMapper and understand its use for object to object mapping. But now EFCodeFirst,dapper and Petpoco all cools stuff are there which will allow us to use our POCO directly with database?
So can anybody let me know why we still need automapper?
Thanks in advance
Best Regards,
Jalpesh
I usually use Automapper to map Domain models to view mdoels. If doing DDD it is often suggested that it's not a great idea to use your Domain models in you views - views often have a different set of concerns to the domain.
For example, you may have a User model in your domain:
public class User
{
public int Id {get;set;}
public string EmailAddress {get;set;}
public string FirstName {get;set;}
public string Surname {get;set;}
public string HashedPassword {get;set;}
public string EyeColour {get;set;}
}
And you may have a User summary page which shows a subset of these items:
public class UserSummary
{
public string EmailAddress {get;set;}
public string Surname {get;set;}
}
You could use the UserSummary class on the view, but you would probably fetch the domain user model from the db. In this case you could use Automapper to map the Domain.User to the ViewModel.UserSummary
var user = _repository.Get(1);
var viewmodel = Automapper.Map<Domain.User, ViewModel.UserSummary>(user);
return View(viewmodel);
I have an aggregate named Campaigns every with a root entity named campaign, this root entity has a list of attempts (entity)
public class Attempts: IEntity<Attempts>
{
private int id;
public AttempNumber AttemptNumber {get;}
//other fields
}
public class Campaign: IEntity<Campaign> //root
{
private int id;
public IList<Attempt> {get;}
//other fields
}
Im using a method to add a campaign attempt
public virtual void AssignAttempts(Attempts att)
{
Validate.NotNull(att, "attemps are required for assignment");
this.attempts.add(att);
}
Problem comes when i try to edit a specific item in attempts list. I get Attempt by AttempNumber and pass it to editAttempt method but i dont know how to set the attempt without deleting whole list and recreate it again
public virtual void EditAttempts(Attempts att)
{
Validate.NotNull(att, "attemps are required for assignment");
}
Any help will be appreciated!
Thanks,
Pedro de la Cruz
First, I think there may be a slight problem with your domain model. It seems to me like 'Campaign' should be an aggregate root entity having a collection of 'Attempt' value objects (or entities). There is no 'Campaigns' aggregate unless you have a parent concept to a campaign which would contain a collection of campaigns. Also, there is no 'Attempts' entity. Instead a collection of 'Attempt' entities or values on the 'Campaign' entity. 'Attempt' may be an entity if it has identity outside of a 'Campaign', otherwise it is a value object. The code could be something like this:
class Campaign {
public string Id { get; set; }
public ICollection<Attempt> Attempts { get; private set; }
public Attempt GetAttempt(string id) {
return this.Attempts.FirstOrDefault(x => x.Number == id);
}
}
class Attempt {
public string Number { get; set; }
public string Attribute1 { get; set; }
}
If you retrieve an Attempt from the Campaign entity and then change some of the properties, you should not have to insert it back into the campaign entity, it is already there. This is how the code would look if you were using NHibernate (similar for other ORMs):
var campaign = this.Session.Get<Campaign>("some-id");
var attempt = campaign.GetAttempt("some-attempt-id");
attempt.Attribute1 = "some new value";
this.Session.Flush(); // will commit changes made to Attempt
You don't need an Edit method. Your code can modify the Attempts in-place, like so:
Attempt toModify = MyRepository.GetAttemptById(id);
toModify.Counter++;
toModify.Location = "Paris";
MyRepository.SaveChanges(); // to actually persist to the DB
Of course how you name the SaveChanges() is up to you, this is the way Entity Framework names its general Save method.