What is the best method to returned value of update method
is True to return whole updated row if only one filed updated in this row
Or only should return success message and during this message, should programmer re render interface with updated values
If you're talking REST, the client will PUT a resource, while the server will update it, and then return a response containing feedback. This can be the HTTP Status Code, and either be the updated resource (if successful) so that the client can use it (without submitting a new GET request), or an error resource so that the client can know what went wrong (and possibly correct that).
Now if this update will translate into multiple table and even row updates, that's just your internal implementation, of which the client doesn't know about - all he knows is the contract, represented by the resource.
Related
I'm working on a gRPC API that has a database with an endpoint to return a record back to the consumer. One of the columns is an enum string {X|Y|Z}. When returning the record, I reverse map the enum to an int.
IF someone edits the data to maliciously insert 'M' into the column, the reverse mapping fails. In this case, what's the gRPC error code that needs to be returned?
DATA_LOSS or FAILED_PRECONDITION or INTERNAL ?
As per the Unrecoverable data loss or corruption.. Does this mean, data is not longer recoverable by any means or the API was not able to act based on the data it fetched from the db?
I have been reading about MediatR and CQRS latelly and I saw many people saying that commands shouldn't return domain objects. They can return values but they're limited to returning erros values, failure/success information and the Id of the newly created entities.
My question is how to return this new objetct to the client if the command can return only the Id of the new entity.
1) Should I query the database again with this new Id? If so, isn't that bad that I making a new trip to the database to get an object that was in the memory a few seconds ago?
2) What's the correct way of returning the entities created by the commands?
I think the more important question is why you shouldn't return domain objects from commands. If the reason for that seems like a valid reason for you, you should look into alternatives such as executing a query right after the command to fetch the domain object.
If, however, returning the domain object from the command fits your needs and does not impose any direct problems, then why not just do it and keep things simple and straightforward?
I am trying to gather a range of messages through the rest API, and am aware that you can only retrieve 20 results at a time. I have tried incrementing a page variable, but this has no affect, and I am just getting the same results each time no matter the page number (https://www.yammer.com/api/v1/messages.json?page=6). I have proceeded to use the newer_than and older_than parameters to page through the results, and it works to some extent, but it appears to be excluding records. I am using the following approach below:
Since just setting a newer_than only results in the 20 most recent records as long as they are newer than the id that is sent in the newer_than parameter, I am also setting a dynamic older_than parameter.
Send request with only a newer than parameter. This returns the 20 most recent records. (eg. ww.yammer.com/api/v1/messages.json?newer_than=235560157)
Extract the ID of the 20th id in the JSON, and using this to populate the older_than parameter. The result is 20 different records. (eg.ww.yammer.com/api/v1/messages.json?newer_than=235560157&older_than=405598096)
Repeat step 2 until no results are returned since the newer_than and older_than parameters will eventually overlap.
The problem is that the set of records that is returned with this method is less than the number of records that is returned for messages from the data export API. I am working under the assumption that newer message IDs are always generated with a value greater than any older messages.
Could I possibly be misunderstanding how paging through results is supposed to be implemented with the REST API?
Any help would be much appreciated!
Thanks in advance!
First of all, the page parameter works only for the search API.
Secondly, the way you are trying to fetch messages will not return any comments on the messages or will return top 2 comments on any message based on the "extended" parameter. By default it returns 2 comments on every message. To get all the comments on the message you will have to get it individually message wise.
That must be causing the difference in the number of messages in the two methods mentioned.
I agree with Farhann - The rest API endpoint returns only top two comments for any message by default. To get all the comments for a post, you have to make a separate request.
With the use of the Data Export API, all the comments along with the message (public and private) are also exported which increases the count of the number of the messages. While, the API call returns only recent 2 comments on any message by default.
The data export includes private messages. Private messages will not be returned by that API call.
Check if the messages you are not seeing are private messages.
I'm new to Backbone.js. I'm intrigued by the idea that you can just supply a URL to a collection and then proceed to create, update, delete, and get models from that collection and it handle all the interaction with the API.
In the small task management sample applications and numerous demo's I've seen of this on the web, it seems that the collection.fetch() is used to pull down all models from the server then do something with them. However, more often than not, in a real application, you don't want to pull down hundreds of thousands or even millions of records by issuing a GET statement to the API.
Using the baked-in connection.sync method, how can I specify parameters to GET specific record sets? For example, I may want to GET records with a date of 2/1/2014 or GET records that owned by a specific user id.
In this question, collection.find is used to do this, but does this still pull down all records to the client first then "finds" them or does the collection.sync method know to specify arguments when doing a GET to the server?
You do use fetch, but you provide options as seen in collection.fetch([options]).
So for example to obtain the one model where id is myIDvar:
collection.fetch(
{
data: { id: myIDvar },
success: function (model, response, options) {
// do a little dance;
}
};
My offhand recollections is that find, findWhere and where would invoke all models being downloaded and then the filtering taking place on the client. I believe with fetch the filtering takes places on the server side.
You can implement some kind of pagination on server side and update your collection with limited number of records. In this case all your data will be up to date with backend.
You can do it by overriding fetch method with you own implementaion, or specify params
For example:
collection.fetch({data: {page: 3})
You can also use find where method here
collection.findWhere(attributes)
Out of the blue, i am getting this error when doing a number of updates using nhibernate.
Row was updated or deleted by another transaction (or unsaved-value mapping was incorrect): [MyDomainObject]
there is no additional information in the error. Is there some recommended way to help identify the root issue or can someone give me a better explanation on what this error indicated or is a sympton around.
Some additional info
I looked at the object and all of the data looks fine, it has an ID, etc . .
Note this is running in a single call stack from an asp.net-mvc website so i wouldn't expect there to be any threading issues to worry about in terms of concurrency.
NHibernate has an object, let's call it theObject. theObject.Id has a value of 42. NHibernate notices that the object is dirty. The object's Id is different than the unsaved-value, which is zero (0) for integer primary keys. So NHibernate issues an update statement, but no rows are updated, which means that there is no row in the database for that type of object with an Id of 42. So the object has been deleted without NHibernate knowing about it. This could happen inside another transaction (e.g. you have threading issues) or if someone (or another application) deleted/altered the row using SQL directly against the database.
The other possibility is that your unsaved-value is wrong. e.g. You are using -1 to indicate an unsaved-entity, but your mapping has a unsaved-value of zero. This is unlikely as your application is generally working from the sounds of it. If the unsaved-value was wrong, you wouldn't have been able to save any entities to the database as NHibernate would have been issuing UPDATE statements when it should have been issuing INSERT.
It means that you have multiple transactions accessing the same data, thus producing concurrency issues. You should improve on your data access handling, you probably are updating data from multiple threads, syndicate the changed data into a queue first which handles all the access to the db.
An old post, but hopefully my info will help someone. I was getting a similar error but only when persisting associations, after I had added in a new object. The error was of the form:
NHibernate.StaleObjectStateException: Row was updated or deleted by another transaction (or unsaved-value mapping was incorrect) [My.Entity#0]
Note the zero on the end, which is my identifier property. It should not be trying to save with key zero as I was using identity specification in SQL Server (generator class=native). I had not changed my unsaved-value in my xml so I had no idea what the problem was; for some reason NHibernate was trying to do an update using key value as 0 instead of a save (and getting the next key identity) for my new object.
In the end I found the cause was that I was initialising Version number to 1 for the new object in my constructor! Even though my identifier property was zero, for some reason NHibernate was also looking for a version property of zero as well, to identify it as an unsaved transient instance. The book "NHibernate in Action" does actually mention this on page 120, but for some reason my objects were fine when persisting with version number of 1 normally, and only failing if saving a new object through an association.
So make sure you do not set your Version value (leave as zero or null).
You say that your data is ok, but check if for example you are mapping the ID as self generate. I had the exact same problem, but I was sending an object with an ID different from 0.
Hope it helps!
My problem was this:
[Bind(Include="Name")] EventType eventType
Should have been:
[Bind(Include="EventTypeId,Name")] EventType eventType
Just as other answers suggest nhibernate was using zero as the id for my entity.
If you have a trigger on the table, it can be the reason. In this case, add inside it
SET ROWCOUNT 0;
SET NOCOUNT ON;
This error happened to me in the following way:
List < Device > allDevices = new List < Device > ();
//Add Devices to the list
allDevices.Add(aDevice);
//Add allDevices to database //Will work fine
// allDevices.Clear(); //Should be used here
//Later we add more devices
allDevices.Add(anotherDevice);
//Add allDevices to Database -> We get the error
//Solution to this
allDevices.Clear(); //Before adding new transaction with the oldData,