I have a little problem filtering data...I have a relation many to many.
Sponsor and Old
I have one intermediary table with both ids...
When I log in, my session save a Sponsor id...but when I go to see Old view, appears every Olds... How to access the intermediary table from the OldController or the SponsorController?
In my Oldcontroller I have:
def index(Integer max) {
params.max = Math.min(max ?: 10, 100)
def sponsor = Sponsor.findById(session.getAttribute("id"))
def myOld = Old.findAllBySponsor(sponsor, params)
def allMyOld = Old.findAllBySponsor(sponsor)
respond myOld, model:[oldInstanceCount: allMyOld.size()]
//respond Old.list(params), model:[oldInstanceCount: Old.count()]
}
But returns unexpected NullpointerException when processing request: [GET] /oldCare/old/index
No value specified for parameter 2.. Stacktrace follows:
Message: No value specified for parameter 2.
How I access the intermediary table for filtering the olds and appears just the Old associated a one Sponsor?
Assuming you have the following :
class Old {
String title
static hasMany = [sponsours: Sponsour]
}
class Sponsour {
String name
static hasMany = [olds:Old]
}
To find :
def sponsor = Sponsor.load(session.getAttribute("id"))
def allMyOlds = Old.findBySponsour(sponsor,params)
Related
So the context is that I require to update a value in a single document, I have a Mono, the parameter Object contains values such as username (to find the correct user by unique username) and an amount value.
The problem is that this value (due to other components of my application) is the value by which I need to increase/decrease the users balance, as opposed to passing a new balance. I intend to do this using two Monos where one finds the user, then this is combined to the other Mono with the inbound request, where I can then perform a simple sum (i.e balance + changeRequest.amount) then return this to the document database.
override fun increaseBalance(changeRequest: Mono<ChangeBalanceRequestResource>): Mono<ChangeBalanceResponse> {
val changeAmount: Mono<Decimal128> = changeRequest.map { it.transactionAmount }
val user: Mono<User> = changeRequest.flatMap { rxUserRepository.findByUsername(it.username)
val newBalace = user.map {
val r = changeAmount.block()
it.balance = sumBalance(it.balance!!, r!!)
rxUserRepository.save(it)
}
.flatMap { it }
.map { it.balance!! }
return Mono.just(ChangeBalanceResponse("success", newBalace.block()!!))
}
Obviously I'm trying to achieve this in a non-blocking fashion. I'm also open to using only a single Mono if that's possible/optimal. I also appreciate I've truly butchered the example and used .block as a placeholder to illustrate what I'm trying to achieve.
P.S this is my first post, so any tips on how to express my problem clearer would be useful.
Here's how I would do this in Java (Using Double instead of Decimal128):
public Mono<ChangeBalanceResponse> increaseBalance(Mono<ChangeBalanceRequestResource> changeRequest) {
Mono<Double> changeAmount = changeRequest.map(a -> a.transactionAmount());
Mono<User> user = changeRequest.map(a -> a.username()).flatMap(RxUserRepository::findByUsername);
return Mono.zip(changeAmount,user).flatMap(t2 -> {
Double changeAmount = t2.getT1();
User user = t2.getT2();
//assumes User is chained
return rxUserRepository.save(user.balance(sumBalance(changeAmount,user.balance())));
}).map(res -> new ChangeBalanceResponse("success",res.newBalance()))
}
I have a Java program that I must implement in Scala, but I am extremely new to Scala. After reading a number of SO question & answers as well as reading through a number of Google-retrieved resources on case classes, I am still having trouble grasping how to acquire a reference to the message I received? Example code is below:
case class SpecialMessage(key: Int) {
val id: Int = Main.idNum.getAndIncrement().intValue()
def getId(): Int = {
return id
}
}
Then in another class's receive I am trying to reference that number with:
def receive() = {
case SpecialMessage(key) {
val empID = ?? getId() // Get the id stored in the Special Message
// Do stuff with empID
}
}
I cannot figure out what to put on the right sight of empID = in order to get that id. Is this really simple, or something that isn't normally done?
These are 2 ways to do what you want, pick the one that suits best
case msg: SpecialMessage => {
val empID = msg.getId() // Get the id stored in the Special Message
// Do stuff with empID
}
case msg # SpecialMessage(key) => {
val empID = msg.getId() // Get the id stored in the Special Message
// Do stuff with empID
}
Pim's answer is good.
But maybe you can modify the structure of SpecialMessage like
case class SpecialMessage(key: Int,val id: Int = Main.idNum.getAndIncrement().intValue())
so you can get id directly from pattern matching.
def receive() = {
case SpecialMessage(key, empID) {
// Do stuff with empID
}
}
Not able to get the list of Objects when a hasMany attribute is null.
Class User {
...
List<EMail> emails
static hasMany = [emails: EMail,... ]
static mappedBy = [emails: 'customer',...]
...
}
Where Email is another Class with some String Attributes
Now i am trying to make a simple query as:
Method 1:
def users = User.findAllByEmailsIsEmpty()
This is giving Error as:
Queries of type IsEmpty are not supported by this implementation
Method 2:
def users = User.findAllByEmailsIsNull()
This is giving all the users even those have Email object associated with it.
Then I thought of trying Criteria Query (https://grails.github.io/grails-doc/latest/ref/Domain%20Classes/createCriteria.html )
Method 3:
def userCriteria = User.createCriteria()
def users = userCriteria.list(){
sizeEq('emails', 0)
}
This gives No result ( users.size() is 0 )
Method 4:
def userCriteria = User.createCriteria()
def users = userCriteria.list(){
isNull('emails')
}
This again gives all the Users even those who don't have emails.
Method 5:
def userCriteria = User.createCriteria()
def users = userCriteria.list(){
isEmpty('emails')
}
This gives the Error :
Queries of type IsEmpty are not supported by this implementation
Method 6:
def userCriteria = User.createCriteria()
def users = userCriteria.list(){
eq('emails', null)
}
This again lists down all the users.
PS: Grails is configured with Database as MongoDB.
I would use the grep method. Something like this:
nullEmailUsers = User.list().grep {
!it.emails
}
User.findAll { emails.id != null } do the job!
Ok, I must be working too hard because I can't get my head around what it takes to use the Entity Framework correctly.
Here is what I am trying to do:
I have two tables: HeaderTable and DetailTable. The DetailTable will have 1 to Many records for each row in HeaderTable. In my EDM I set up a Relationship between these two tables to reflect this.
Since there is now a relationship setup between these tables, I thought that by quering all the records in HeaderTable, I would be able to access the DetailTable collection created by the EDM (I can see the property when quering, but it's null).
Here is my query (this is a Silverlight app, so I am using the DomainContext on the client):
// myContext is instatiated with class scope
EntityQuery<Project> query = _myContext.GetHeadersQuery();
_myContext.Load<Project>(query);
Since these calls are asynchronous, I check the values after the callback has completed. When checking the value of _myContext.HeaderTable I have all the rows expected. However, the DetailsTable property within _myContext.HeaderTable is empty.
foreach (var h in _myContext.HeaderTable) // Has records
{
foreach (var d in h.DetailTable) // No records
{
string test = d.Description;
}
I'm assuming my query to return all HeaderTable objects needs to be modified to somehow return all the HeaderDetail collectoins for each HeaderTable row. I just don't understand how this non-logical modeling stuff works yet.
What am I doing wrong? Any help is greatly appriciated. If you need more information, just let me know. I will be happy to provide anything you need.
Thanks,
-Scott
What you're probably missing is the Include(), which I think is out of scope of the code you provided.
Check out this cool video; it explained everything about EDM and Linq-to-Entities to me:
http://msdn.microsoft.com/en-us/data/ff628210.aspx
In case you can't view video now, check out this piece of code I have based on those videos (sorry it's not in Silverlight, but it's the same basic idea, I hope).
The retrieval:
public List<Story> GetAllStories()
{
return context.Stories.Include("User").Include("StoryComments").Where(s => s.HostID == CurrentHost.ID).ToList();
}
Loading the the data:
private void LoadAllStories()
{
lvwStories.DataSource = TEContext.GetAllStories();
lvwStories.DataBind();
}
Using the data:
protected void lvwStories_ItemDataBound(object sender, ListViewItemEventArgs e)
{
if (e.Item.ItemType == ListViewItemType.DataItem)
{
Story story = e.Item.DataItem as Story;
// blah blah blah....
hlStory.Text = story.Title;
hlStory.NavigateUrl = "StoryView.aspx?id=" + story.ID;
lblStoryCommentCount.Text = "(" + story.StoryComments.Count.ToString() + " comment" + (story.StoryComments.Count > 1 ? "s" : "") + ")";
lblStoryBody.Text = story.Body;
lblStoryUser.Text = story.User.Username;
lblStoryDTS.Text = story.AddedDTS.ToShortTimeString();
}
}
I have an entity with two fk's. I've been trying to insert a record to the database without success. This are the approaches I've used:
valuePaymentBetToAdd.BetType = db.BetTypes.First(betType => betType.Id == valuePaymentBetToAdd.BetType.Id);
valuePaymentBetToAdd.Lottery = db.Lotteries.First(lotto => lotto.Id == valuePaymentBetToAdd.Lottery.Id);
In this case the second object gets assigned but when calling the SaveChanges method I get an error saying that the properties of the Lottery object were null.
valuePaymentBetToAdd.BetTypeReference.EntityKey = new EntityKey(db.DefaultContainerName + ".BetType", "Id", valuePaymentBetToAdd.BetType.Id);
valuePaymentBetToAdd.LotteryReference.EntityKey = new EntityKey(db.DefaultContainerName + ".Lottery", "Id", valuePaymentBetToAdd.Lottery.Id);
In this case I get another weird error. When the object is being added to the collection.
The object could not be added or attached because its EntityReference has an EntityKey property value that does not match the EntityKey for this object.
Am I missing something in this case?
Try setting the EntityReference like this:
valuePaymentBetToAdd.BetTypeReference.EntityKey = b.BetTypes.First(betType => betType.Id == valuePaymentBetToAdd.BetType.Id).EntityKey;
It works for me
How about creating a stub object for BetType and Lottery where you set only the Id property, and then attach those to their respective EntitySets, and then setting these objects on you Bet object, and save - something like:
Lottery lottery = new Lottery() { Id = valuePaymentBetToAdd.Lottery.Id };
BetType betType = new BetType() { Id = valuePaymentBetToAdd.BetType.Id };
MyContext.AttachTo("Lottery", lottery);
MyContext.AttachTo("BetType", betType);
valuePaymentBetToAdd.Lottery = lottery;
valuePaymentBetToAdd.BetType = betType;
MyContext.AddToBet(valuePaymentBetToAdd);
MyContext.SaveChanges();