I'm using Slick to query a database. I pass a Case class to my query method which looks like similar to...
case class queryParams(id:Int, age:Option[Int] = None,
categoryId:Option[Int] = None)
I have a Slick query that is similar to...
val query = this.filter( row =>
(row.id == queryParams.id))
query.list
And this works fine. But what I want to do now is extend the query to include the other queryParams members "if" they are defined but I'm unsure how I should structure this.
What I want is something like this...
for { row <- this.list
if(row.id == queryParams.id)
// include
if(queryParams.age.isDefined) row.age == queryParams.age.get
} yield row
How can I include optional params in the query?
Thanks
I ended up using a custom "MaybeFilter" solution that is posted in various places including...
See https://gist.github.com/studiodev/5c6471cb1d823914ee28
Related
I'm using the Mongo LINQ Driver for C#, works great.
Sorting a lot of properties but heres a problem I can't solve, its probably simple.
var identifierList = new []{"10", "20", "30"};
var newList = list.Where(x => identifierList.Contains(x.Identifier));
This is NOT supported ...
So I could do something like:
var newList = list.Where(x => x.Identifier == "10" || x.Identifier == "20" || x.Identifier == "30");
But since the list is variable ... how do I construct the above? Or are there even better alternatives?
The list is of type IQueryable<MyCustomClass>
For information ... this is used as a filter of alot of properties. In SQL I could have a parent -> child relationship. But as I can't as the parent for the main ID I need to take all the ID's out and then construct it like this.
Hopes this makes sense. If needed I will explain more.
To answer my own question ... The Mongo Sharp LINQ driver has an extension method called "In" which does exactly what I need.
They have however implemented it in 1.5 so we can use the old way like: https://jira.mongodb.org/browse/CSHARP-462
var list = new []{"10", "10"};
search.Where(x => list.Contains(x.Id));
But the version 1.5 package is not on nuget yet.
However, this should work with the "In" extension that comes as a special surprise with the mongo-csharp-driver.
search.Where(x => x.In(list));
var identifierList = new []{"10", "20", "30"};
var newList = list.ToList().Where(x => identifierList.Contains(x.Identifier));
You will just have to use List instead of Ienumerable (do that by using the .ToList())
If it doesn't work please add your list TYPE
I have use case where I need to read value from query string.
Currently I have two different APIs(Some other person has created the code) which maps to same URL
GET /service/class/:className/details controllers.Student.getStudentDetails(studentId)
GET /service/class/:className/details controllers.Student.getAllStudentsDetails()
If query string is present in URL then API1 should execute, otherwise API2.
As URL is same for both APIs, I am able to hit only get-student-details API(Because it has higher priority in routes file).
I am looking for alternatives to fix this problem.
As per my knowledge we don't need to create different APIs just to handle query strings.
I am thinking to merge 2 different APIs in single APIs which takes action depending upon presence of query string in request.
What I want to know is if there is way to execute two different APIs which maps to same URL(Only difference is with query string).
NOTE: I am using play 2.4.6.
I see few ways using a single controller function (say we chose getStudentDetails)
1) Having an Option parameter:
def getStudentDetails(studentId: Option[String]) = Action { studentId match {
case Some(id) => // do something
case None => // do something else
}
// ..
}
2) Look for your query string parameters inside your http request:
def getStudentDetails = Action { request =>
request.queryString.get("studentId") match {
case Some(list) => // do something...beware this is a List
case None => // do something else
}
//...
}
I'm using Play Framework and client can send only some fields to update in database. Then I need to do something like this:
g.copy(
partnumber = jGood.partnumber,
cost = jGood.cost
)
So, most of the fields I will have in jGood will be None and only some of them will be Some. Now how can I filter all those None fields and make a copy of class only with Some fields?
Consider this:
g.copy(
partnumber = jGood.partnumber.orElse(g.partnumber),
cost = jGood.cost.orElse(g.cost)
)
I am trying to perform an update using strongly-typed objects. For example,
public void setAppointmentPrefs(string UserName, IEnumerable<AppointmentInfo> info)
{
var query = new QueryDocument {{ "ProviderId", UserName}};
var update = Update.Set("Prefs",prefs); // prefs.toList() gives same error
// providerprefs initialized in constructor
providerprefs.Update(query, update);
}
I receive a compiler error saying:Error 14 The best overloaded method match for 'MongoDB.Driver.Builders.Update.Set(string, MongoDB.Bson.BsonValue)' has some invalid arguments
Obviously the Mongo driver will not let me update based on my own object (whether as IEnumerable or prefs.toList()), which seems a contrast from the way it permits me to insert or query with custom objects. Surely I am missing something obvious that would permit me to avoid deserializing, weakly typing then creating a generic BsonDocument!! TIA.
You can do an Update based on your own types! Have you tried using the typed Query and Update builders?
Try something like this:
var query = Query<AppointmentInfo>.EQ(i => i.ProviderId, userName);
var update = Update<AppointmentInfo>.Set(i => i.Prefs, info.Prefs);
Not sure I got the types and everything write from your partial code, but that should give you the general idea.
Let me know if you have any further questions.
I know this has been answered but I for one don't fully understand Roberts answer.
All I did is call the "ToBsonDocument()" method for it to except the object as a parameter
So:
customObject.ToBsonDocument()
If you have an array of objects inside a document:
var query = Query.EQ("_id", ObjectId.Parse(id.ToString()));
var update = Update.Push("ArrayOfObjects", customObject.ToBsonDocument());
collection.Update(query, update);
Is there a way of creating method for setting the value in the Model's fields without setting the values explicitly like -
ModelName.create.fieldName1("value").fieldName2("value2") and so on
Can we iterate through all available fields of that model and set their values form some list-of-values ?
something like ...
Model.allFields.foreach((fld)=> {
fld.set(valueList(indx)); indx+=1
}
Actually I want to set values into all models using some generic method that works for all models.
According to my comment:
val list = List(...)
val record = YourRecordClass.createRecord
record.allFields.zip(list).foreach {case(field,value) => field.setFromAny(value)}