everyone!
I have the following situation: client sends attributes, which he wants to retrieve from table, for example "Id, Name, Price", and I should send them , having been mapped them before. The problem is, how to find out what are the types of given attribute? I want to know where the data of Price attribute is stored: val["Price"].N or val["Price"].S or somewhere else? Is there any way to find it out?
Thank you for any advice!!!
I am not familiar with the .net SDK specifically, but if you are looking for what data type each attribute is stored in DynamoDB, you could do the calls with the low level client in the SDK, as opposed to the DocumentClient. The low level client returns DynamoDB's native JSON format and will tell for each attribute if it is a string, number, map, etc.
Related
We are trying to implement Customer oriented details in Graphdb, were with a single query we can fetch the details of a customer such as his address,phone,email etc. We have build it using had address, has email edges..
g.addV('member').property('id','CU10611972').property('CustomerId', 'CU10611972').property('TIN', 'xxxx').property('EntityType', 'Person').property('pk', 'pk')
g.addV('email').property('id','CU10611972E').property('pk', 'pk')
g.addV('primary').property('id','CU10611972EP').property('EmailPreference','Primary').property('EmailType', 'Home').property('EmailAddress', 'SNEHA#GMAIL.COM').property('pk', 'pk')
g.V('CU10611972').addE('has Email').to(g.V('CU10611972E'))
g.V('CU10611972E').addE('has Primary Email').to(g.V('CU10611972EP')
This is how we have build email relation to the customer.. Similarly we have relations with Address and Phone. So right now we are using this command to fetch the json related to this customer for email,
g.V('CU10611972').out('has Email').out('has Primary Email')
And for complete Customer details we are using union for each Vertex, Phone,Emaiul and address..
Could you please suggest if there is an efficient way to query this detail?
This comes down really to two things.
General graph data modelling
Things the graph DB you are using does and does not support.
With Gremlin there are a few ways to model this data for a single vertex.
If the database supports it, have a list of names like ['home','mobile'] and use metaproperties to attach a phone number to each.
A lot of the Gremlin implementations I am aware of have chosen not to support meta properties. In these cases you have a couple of options.
(a) Have a property for 'Home' and another for 'Mobile'. If either is not known you could either not create that property or give it a value such as "unknown"
(b) Use prefixed strings such as ["Home:123456789","Mobile:123456789] and store them in a set or list (multi properties) and access them in Gremlin using the startingWith predicate. Such as g.V(id).properties('phone').hasValue(startingWith('Mobile')).value()
Say, we have an api which returns a list of employee records. Each record has a gender field whose value may be 'MALE' or 'FEMALE'. We want to show the gender of each employee with a message which may be 'Male' or 'Female'.
To achieve the goal above, we have following options:
Return both the value and the message so the client doesn't bother
Return the value only and let client determine the appropriate message
Which one is better?
It does depend. If you plan to give a uniform vision about your backend data and potentially there will be N API Consumer that will use your service, I'd prefer the first option. This can come in handy if you have to tackle to internationalization issue
I'm looking for a fast & elegant way of converting my object IDs with descriptive names, so that my autogenerated routes look like:
/products/oak-table-25x25-3-1
instead of
/products/5bd8c59c-fc37-40c3-bf79-dd30e79b55a5
In this sample:
uid = "5bd8c59c-fc37-40c3-bf79-dd30e79b55a5"
name = "Oak table (25x25) 3/1"
I don't even know how that feature could be named, so that I might google for it.
The problem that I see so far is the uniqueness of that "url-object-name", for example if I have two oak tables 25x35 in the db, and their names differ too little to be uniquely url-named but enough to fool the unique constraint in the db.
I'm thinking of writing that function for name-transform in SQL as an UDF, then adding a calculated field that returns it, then unique-constraining that field.
Is there some more mainstream way of achieving that?
One method is that employed by stackoverflow.com which in your case would be:
/products/5bd8c59c-fc37-40c3-bf79-dd30e79b55a5/oak-table-25x25-3-1
This ensures uniqueness, however the length of the UUID may be a deterrent. You may consider adding a sequential int or bigint identity value to the products table in addition to the uniqueidentifier field. This however would require an additional index on that column for lookup, though a similar index would be required for a Url having only a descritive string. Yet another method would be to use a hash value, seeded by date for instance, which you can compose with the descriptive name. It is simpler to rely on a sequential ID value generated by a database, but if you envision use NoSQL storage mechanisms in the future you may consider using an externally generated hash value to append.
Identity should have 2 properties: it should be unique and unchangable. If you can guarantee, that /products/oak-table-25x25-3-1 will never change to /products/oak-table-25x25-3-1-1 (remember, user can have bookmarks, that shouldn't return 404 statuscode)- you can use name as url parameter and get record by this parameter.
If you can't guarantee uniqueness or want to select record more faster - use next:
/products/123/oak-table-25x25-3-1 - get record by id (123)
/products/123/blablabla - should redirect to first, because blabla no exists or have anoher id
/products/123 - should redirect to first
And try to use more short identities - remember, that at web 2.0 url is a part of UI, and UI should be friendly.
MVC routing (actions) will handle spaces and slashes in a name. It will encode them as %20, and then decode them correctly.
Thus your URL would be /products/oak%20table%2025x25-3%2F1
I have done something very similar in an eCommerce platform I am working on.
The idea is that the URL without the unique ID is better for SEO but we didn't want the unique ID to be the product name that can change often.
The solution was to implement .NET MVC "URL slug only" functionality. The product manager creates "slugs" for every product that are unique and are assigned to products. These link to the product but the product ID and name can be changed whenever.
This allows:
domain.com/oak-table-25x25-3-1
to point to:
/products/5bd8c59c-fc37-40c3-bf79-dd30e79b55a5
(The same functionality can be used on categories too so domain.com/tables can point to domain.com/category/5b38c79c-f837-42c3-bh79-dd405479b15b5)
I have documented how I did this at:
http://makit.net/post/3380143142/dotnet-slug-only-urls
I have a stored procedure that search a view using full text.
I'm trying to map the results to an existing Entity (Sales), where I mapped the column MivType to SaleType (as it makes more sense, and I want to keep db names away from my web site). The stored procedure is mapped to a Function Import, and I've defined its ReturnType to Sales.
This work well as long as the entity has the same property names as fields names.
Here's my problem: when I change the property's name, I get the following error after running the imported function:
The data reader is incompatible with the specified 'Model.Sale'. A member of the type, 'SaleType', does not have a corresponding column in the data reader with the same name.
I can fix this if I change the property 'SaleType' to 'MivType' on the entity, but why should I do that? Isn't that what the mapping is for?
This means I have to use the exact same names on the stored procedure and the entity, so in effect, the mapping is ignored (I have names like YzrName, MivYaad, etc, and I don't like it).
Is there a simple way around this? I don't want to use the db names on my application, and prefer not to change the stored procedure...
(I should mention I'm a beginner with the EF, so this can be a rookie mistake)
Thanks.
Well the entity designer doesnt work very well. I generally try to do everything in the XML. In the XML there are 3 parts. The Storage (a representation of the SQL Database). The Conceptual (a represention of your .Net Objects. and the Conceptual to Storage Mapping
It sounds like the error is in your Conceptual to Storage Mapping. You can keep the property name SalesType on the conceptual side but the mapping must map the the correct names on both the conceptual and storage side.
Refer to MSDN here are some articles
http://msdn.microsoft.com/en-us/library/cc716731.aspx
Using the Dynamics CRM I'm trying to create an instance of an entity. I would like to manually set the GUID, but if I had the attribute that is the primary key to the DynamicEntity, I get following error.
Service could not process request
I am building a DynamicEntity, and setting the [entityname]id attribute causes the request to fail. It's moving data between two CRM instances, so if anyone knows of a better way to copy records between CRMs, that'd work too. Otherwise, I'd like the GUID to match across instances... as that's the point of a GUID.
Happily, it IS possible to do this across two CRM instances! A co-worker knew the solution, so credit really belongs to him.
My mistake was creating a Property with type UniqueIdentifierProperty. The primary key attribute on an entity needs to be filled in with a KeyProperty. These two properties are nearly identical -- the Property types are, except that one holds a Key, the other a UniqueIdentifier. The Key/UniqueIdentifier both hold GUIDs. (Another day in the mind of Microsoft!)
Precisely, what I'm doing is creating a DynamicEntity, filling in the entity name, and filling in the majority of the attributes. The PK attribute (which you can determine from the metadata) can be filled in with a KeyProperty. I was filling it in with a UniqueIdentifierProperty, which CRM rejects and responds with a nondescript and unhelpful error message.
I apologize if I am over-simplifying the solution, but why not add a custom field in both instances that would be a mirror of the other instances guid?