There are multiple knockoutJS resources which show how to sort objects over string values(ex. FirstName, LastName) but couldn't find way to sort using numeric values (ex. Marks, Salary, Age)
This jsfiddle has necessary data and I would like to sort objects in ascending as well as descending direction depending on field 'mark'
I tried using parseIntbut it's not working.
I think you forgot to invoke "mark" as observable here is a working version of your code http://jsfiddle.net/kuedwryz/1/
//use
right.mark()
//instead of
right.mark
Related
I'm building a GraphQL API. I'm want to allow users to specify how records should be sorted, using multiple sorts.
What should be possible
If I expose the ability to sort monsters by name, birthdate, and id, users should be able to get the API to sort by any combination of those, including (in SQL terms):
ORDER BY name ASC
ORDER BY name ASC, birthdate DESC, id ASC
... etc
What won't work
A single map, like this:
sorts: [{name: DESC, id: ASC}]
...would not tell me the order in which the sorts should be applied (maps are unordered).
What works OK, but isn't ideal
Currently, I accept a list of maps, like this:
sorts: [{name: DESC}, {id: ASC}]
Each map represents an input object, which has fields like name and id, which are enums with possible values ASC and DESC. I expect only one field to be filled per input object. ~But I don't know a way to enforce that.~
This is awkward because:
It would be easy for users to typo their sort parameters as a single map
I can't specify a default (like ASC for id) without having it added to every input object map
Is there a more idiomatic way of accepting an ordered list of sort parameters?
Update
I've now added a user-facing explanatory error when there is more than one key per map. With this change, I think this strategy is OK, but I'm still happy to hear of better ways in the future if they arise.
I think the short answer is "no".
Long answer: You can introspect your types at startup, and generate the schema dynamically according to some made-up convention using custom scalars to represent sorting directive, for example:
monsters(sortBy: [name___ASC, birthdate___DESC, id___ASC]) { name }
but this is also "just a convention". The "list of maps" ("array of objects") model that you listed a non-ideal might be the best option at this point:
# the query
monsters(
sortBy: [
{name: asc},
{birthdate: desc_nulls_last},
{id: asc}
]
) {
name
}
BUT, irrespective of which way you choose, avoid the temptation of starting hacking these things in manually - your server code will become convoluted due to this cross-cutting concern, as will your schema.
Instead, I have seen some GraphQL-to-ORM-bridging libraries make use of Directives to control the runtime schema generation (one example of this). That should be much more viable than hand-carving stuff like this.
I have implemented laravel dataTable as a service.
The initial two columns are actual id and names so, I am able to sort it asc/desc after the table renders.
But the next few columns renders after performing few calculations, i.e. these values are not fetched directly from any column rather it is processed.
I am unable to sort these columns where calculations were performed, and I get this error. And I know it is looking for that particular column for eg outstanding_amount which I don't have in the DB, rather it is a calculated amount from two or more columns that are in some other tables.
Any Suggestions on how to overcome this issue?
It looks like you're trying to sort by values that aren't columns, but calculated values.
So the main issue here is to give Eloquent/MySql the data it needs to provide the sorting.
// You might need to do some joins first
->addSelect(DB::raw('your_calc as outstanding_amount'))
->orderBy('outstanding_amount') // asc can be omitted as this is the default
// Anternative: you don't need the value sorted by
// Don't forget any joins you might need
->orderByRaw('your_calc_for_outstanding_amount ASC')
For SQL functions it'll work as follow
->addSelect(DB::raw('COUNT(products.id) as product_count'));
->orderByRaw(DB::raw('COUNT(products.id)'),'DESC');
I want to have multiple sort on datatable. I find below link that seems more match on my case. Initial sortorder for Primeface datatable with multisort
But I have one field that have specified sorting. I have only three different values. e.g. TCS(first in sorting), School-input (second), self-input (third). Their sorting are not on letters as you see. How to handle this?? Do you have any suggestions to help me??
I have solved by adding one more parameter in the class of typeId which will be sorting. typeId is hardcoded assigned to different type string.
I have this here:
Dim query = FromTableRows.Select(Function(Row) Row.Item(_SqlSyntaxChecker.SelectedFields(0)))
Row is a normal DataRow, so I can get the field value of the rows like this: Row.Item(0), Row.Item(1), etc.
SelectedFields contains the field names of the FromTableRows.
Now, I would like to select all the fields in the SelectedFields list, while the number of the selected fields can vary.
Is this possible? How should I modify the code?
Thanks.
You can simply make use of the ItemArray property, if I understand your question correctly.
FromTableRows.Select(Function(Row) Row.ItemArray)
The ItemArray property is an object array that contains the elements found in the DataRow. You will, of course, lose any mapping via this method from columns to elements, but it sounds like that's what you want.
I'm having a problem joining two LINQ queries.
Currently, my (original) code looks like this
s.AnimalTypes.Sort((x, y) => string.Compare(x.Type, y.Type));
What I'm needing to do is change this based on a date, then select all data past that date, so I have
s.AnimalTypes.Select(t=>t.DateChanged > dateIn).ToList()
s.AnimalTypes.Sort((…
This doesn't look right as it's not sorting the data selected, rather sorting everything in s.AnimalTypes.
Is there a way to concatenate the two LINQ lines? I've tried
s.AnimalTypes.Select(t=>t.DateChanged > dateIn).ToList().Sort((…
but this gives me an error on the Sort section.
Is there a simple way to do this? I've looked around and Grouo and OrderBy keep cropping up, but I'm not sure these are what I need here.
Thanks
From your description, I believe you want something like:
var results = s.AnimalTypes.Where(t => t.DateChanged > dateIn).OrderBy(t => t.Type);
You can call ToList() to convert to a List<T> at the end if required.
There are a couple of fundamental concepts I believe you are missing here -
First, unlike List<T>.Sort, the LINQ extension methods don't change the original collections, but rather return a new IEnumerable<T> with the filtered or sorted results. This means you always need to assign something to the return value (hence my var results = above).
Second, Select performs a mapping operation - transforming the data from one form to another. For example, you could use it to extract out the DateChanged (Select(t => t.DateChanged)), but this would give you an enumeration of dates, not the original animal types. In order to filter or restrict the list with a predicate (criteria), you'd use Where instead.
Finally, you can use OrderBy to reorder the resulting enumerable.
You are using Select when you actually want to use Where.
Select is a projection from one a collection of one type into another type - you won't increase or reduce the number of items in a collection using Select, but you can instead select each object's name or some other property.
Where is what you would use to filter a collection based on a boolean predicate.