I'm using NHibernate as my ORM and I'm trying to sort some data. The data needs to be retrieved paged.
Two of the columns in my Request table are UrgencyID and CreateDate. UrgencyID is a FK to the Urgency table with static data:
1 = Low, 2 = Normal, 3 = High, 4 = Critical.
I need to order my Requests in the following manner.
Critical Requests by CreateDate descending
All other requests by CreateDate descending
So my list of Requests should always have Critical by CreateDate desc at the top and then all other Requests (disregarding UrgencyID) by CreateDate desc
Is it possible to perform this sort order in NHibernate (using the Criteria API)?
If not, how would I do this in SQL? In a stored procedure?
EDIT: Solution thanks to both #DanP and #Michael Pakhantsov
Using the this_ prefix in the sql string as this is the default NHibernate prefix for the primary table selection.
public class OperatorJobQueueOrder : Order
{
public OperatorJobQueueOrder() : base("", true) { }
public override NHibernate.SqlCommand.SqlString ToSqlString(ICriteria criteria, ICriteriaQuery criteriaQuery)
{
return new NHibernate.SqlCommand.SqlString("case this_.JobRequestUrgencyID when 4 then 4 else 0 end desc, this_.CreatedDate");
}
}
You may be able to create a custom sort order to handle this through the critiera api; see this question for an example implementation.
IN SQL ORDER BY will be
ORDER by case UrgencyId when 4 then 4 else 0 end, CreateDate desc
Related
I have laravel elqueont collection and i want to sort it based on condition on status value, if status == 3 the ordering will be id desc else the ordering will be id asc, help please.
trying to sort laravel collection based on condition on anthor column value
You can read all about collection sorting on the documentation. So lets say you have 2 conditions your code will look like this
$collection = Model::all();
if($condition == 1) {
$collection->sortBy('created_at');
} else {
$collection->sortByDesc('created_at);
}
This is just a general idea, you can share your code for further help.
I have an endpoint lets say /order/ where i can send json object(my order), which contains some products etc, so my problem is i have to first save the order and wait for the order id back from the db and then save my products with this new order id( we are talking many to many relation thats why theres another table)
Consider this controller method
def postOrder = Action(parse.json[OrderRest]) { req => {
Created(Json.toJson(manageOrderService.insertOrder(req.body)))
}
}
this is how my repo methods look like
def addOrder(order: Order) = db.run {
(orders returning orders) += order
}
how can i chain db.runs to first insert order, get order id and then insert my products with this order id i just got?
im thinking about putting some service between my controller and repo, and managing those actions there, but i have no idea where to start
You can use for to chain database operations. Here is an example of adding a table to a db by adding a header row to represent the table and then adding the data rows. In this case it is a simple table containing (age, value).
/** Add a new table to the database */
def addTable(name: String, table: Seq[(Int, Int)]) = {
val action = for {
key <- (Headers returning Headers.map(_.tableId)) += HeadersRow(0, name)
_ <- Values ++= table.map { case (age, value) => ValuesRow(key, age, value) }
} yield key
db.run(action.transactionally)
}
This is cut down from the working code, but it should give the idea of how to do what you want. The first for statement would generate the order id and then the second statement would add the order with that order id.
This is done transactionally so that the new order will not be created unless the order data is valid (in database terms).
#Query("MATCH (parentD:Decision)-[:CONTAINS]->(childD:Decision)-[ru:CREATED_BY]->(u:User) WHERE id(parentD) = {parentDecisionId} RETURN childD, ru, u ORDER BY childD.createDate DESC")
List<Decision> getChildDecisions(#Param("parentDecisionId") Long parentDecisionId);
Is it possible to pass order expression like childD.createDate and order direction like ASC or DESC via Spring Data Neo4j 4 repository method parameters ? If so, could you please show an example.
Or do I need to use Pageable in this case ?
I have a PrivateMessage class and I want to get list of PMs for user sorted chronologically either by CreationDate or LastAnswerDate (depending on which is more recent) using Criteria API.
How to sort by max of these two properies in Criteria API? My code looks similar to following:
var dc = DetachedCriteria.For<PrivateMessage>();
...
dc.AddOrder(new Order("???");
return (IList<PrivateMessage>)FindAll(typeof(PrivateMessage), dc);
CreationDate is DateTime and LastAnswerDate is DateTime?.
Thanks!
Order.Desc(
Projections.Conditional(
Restrictions.GtProperty("CreationDate", "LastAnswerDate"),
Projections.Property("CreationDate"),
Projections.Property("LastAnswerDate"))))
I have two Tables.
Order - With Columns OrderID, OrderStatusID
OrderStatus - With Columns OrderStatusID, Description
I have an Order Object which calls to the database and fills its properties for use in my code. Right now I have access to Order.OrderStatusID, but in my application I really need access to the "Description" field.
How do you handle this elegantly with good OO design?
Usually I prefer to handle lookups as Value objects. I also use Null Object pattern.
public class Order {
private int statusID;
public OrderStatus Status {
get {
return OrderStatus.Resolve(statusID);
}
set {
statusID = value != null ? value.ID : null;
}
}
}
public class OrderStatus {
public static OrderStatus Resolve(int statusID)
{
OrderStatus status = null;
// read from cache or DB
...
// if not found return Null object
if (status == null)
status = new OrderStatus(null, string.Empty);
return status;
}
}
The system I'm currently working with creates an instance of the other business object and sets the Id. The other business object is then retrieved when it is used. e.g.
Order Properties
int OrderId = 5
int OrderStatusId = 3
OrderStatus OrderStatus_ref
{
get
{
if OrderStatus_ref == null
OrderStatus_ref = new OrderStatus(OrderStatusId)
return OrderStatus_ref
}
}
That's the general idea anyways.
You can use a SQL select statement with a Join to the OrderStatus table, and include the columns yo want from each table ...
Select O.OrderId, O.OrderStatusId, S.Descriptiuon
From Order O
Join OrderStatus S
On S.OrderStatusId = O.OrderStatusId
Where OrderId = 23 -- or whatever
Is it a one-to-one relationship between Order and OrderStatus? I guess it depends on the purpose to why you would have an OrderStatus table as I would argue that there isnt actually any need for a separate OrderStatus table?
Basically all that table gives you is the ability to change the description of the order status. From within code, you would then be writing code according to either a predefined OrderStatusID (from seed data?) or via the description. If this is the case then why not have the Order table contain an OrderStatus column which is an integer and that can map to an enum type?
My Order object would probably include the status description field (readonly [to non internal classes]), as well as any other similar fields.
Under the hood my getters (e.g. LoadByID, LoadAll, etc) would probably use a View (e.g. OrdersView) that contains all of those descriptive fields. Those description fields are readonly so that you don't accidentally set those fields thinking that you can save the changes to the database.