If I want to check to apply Predicate for one particular date, I am able to do so as follows:
predicate = builder.between(root.<LocalDate>get('date'),startDate,endDate);
But now I want to apply for a range of dates.
i.e. if I have an appointment from -> 2020-07-20 to -> 2020-07-25 and,
therefore my range of date is (from, to) here I want to put a check in the predicate that, It want to extract appointment for the date 2020-07-23 then It should be between start and end date.
I don't know if this is a possible case. But as mentioned in above example
I want a query like:
predicate = builder.between(root.<LocalDate>get('range(from, to)'),startDate,endDate);
You'll have to break it in to separate predicates based on startDate, endDate, from and to.
I'm not completely sure I got your intention right, but I think you want to check if the interval [from,to] is completely inside the interval [startDate, endDate]
You can do that with code similar to the following:
Predicate startsAfterBegin = builder.greaterThan(root.get('from'), startDate);
Predicate endsBeforeEnd = builder.lessThan(root.get('to'), endDate);
Predicate isContained = builder.and(startsAfterBegin, endsBeforeEnd);
The fact base stores exam schedule information in the form: exam ('group', 'subject', 'teacher', date). Write a program that allows you to select exam information for the group / teacher, sorting it by date.
So, I already know how to get data from base depending on what you want (by Group number or by teacher name):
exam('426-1', 'PROGRAMMING', 'John', 08-12-2019).
exam('426-1', 'MATH', 'John', 18-12-2019).
exam('426-3', 'ENG', 'Gabe', 16-12-2019).
exam('426-4', 'LITERATURE', 'Homer', 11-12-2019).
findByGroup(Number, Exams) :-
findall([A,B|C], exam(Number, A,B,C), Exams).
findByTeacher(Name, Exams) :-
findall([A,B|C], exam(A, B, Name,C), Exams).
Here's the input
findByGroup('426-1', X).
And here's the output
X = [['PROGRAMMING', 'John'|8-12-2019], ['MATH', 'John'|18-12-2019]]
But I have no idea how should I sort my output by date. For example, how can I sort the data by ascending of the date?
Example:
Before X = [['MATH', 'John'|18-12-2019], ['PROGRAMMING', 'John'|8-12-2019]]
After X = [['PROGRAMMING', 'John'|8-12-2019], ['MATH', 'John'|18-12-2019]]
There are a couple of things that need to be considered:
The date format needs to be in a format that sorts chronologically
The information for each exam item needs to be organized into a term that will sort based upon the date
For the date format, you are using a - functor with integer arguments. This is Ok. To make it sortable chronologically, the order needs to be year-month-day. You can either change your original data to be in that form, or translate to the sortable form before you do your sorting.
Regarding the exam data record, if you create a record formatted as a term with the date as the first argument, then sorting the records will sort by date. For example, any of the following terms will sort by date in Prolog:
exam(Date, Number, A, B)
[Date, Number, A, B]
...etc...
Now we apply this to your problem. Sorting can be done using setof/3 instead of findall/3 if your date is formatted in a sortable form:
% exam(Number, Class, Name, Date)
exam('426-1', 'PROGRAMMING', 'John', 2019-12-08).
exam('426-1', 'MATH', 'John', 2019-12-18).
exam('426-3', 'ENG', 'Gabe', 2019-12-16).
exam('426-4', 'LITERATURE', 'Homer', 2019-12-11).
findByGroup(Number, Exams) :-
setof([Date, Number, Class, Name], exam(Number, Class, Name, Date), Exams).
findByTeacher(Name, Exams) :-
setof([Date, Number, Class, Name], exam(Number, Class, Name, Date), Exams).
This will provide terms with attributes in a slightly different order: [Date, Number, Class, Name]. You can either just work with that, or you could easily change it:
reformat_exam_list([Y-M-D, Number, Class, Name], [Number, Class, Name, D-M-Y]).
And then call maplist(reformat_exam_list, Exams, ReformattedExams).
If you can't change the date format in your original facts, you can pre-process them as part of your setof/3 call.
reformat_sorted_exam(exam(Y-M-D, Number, Class, Name), exam(Number, Class, Name, D-M-Y)).
findByGroup(Number, Exams) :-
setof(exam(Y-M-D, Number, Class, Name), exam(Number, Class, Name, D-M-Y), ExamList),
maplist(reformat_sorted_exam, SortedExams, Exams).
Here I also used an exam structure instead of a list to represent an exam. You get the idea...
Use first two digits of Column to give a name to a new column.
I have a list of companies and their NAICS ID. I would like to filter these into a pie chart but I don't want the 90000 different names (just the general ex. Agriculture or Mining). I want to utilize the first two digits in for the column to identify its general name. I am trying to use the DAX expression Switch to get this started. Is there a filter to do this within PowerBI?
I haven't started yet since I am not sure if this is possible.
You could simply create a calculated column based off of the original NAICS code using the following:
FirstTwoDigitsOfNAICS :=
SWITCH (
TRUE (),
LEFT ( 'Table'[NAICSCode] ) = x, "Something",
LEFT ( 'Table'[NAICSCode] ) = y, "Something Else"
)
This DAX will simply pull the first two characters from the entire code.
I have a the following database of facts like:
...
book(title1, author1),
book(title2, author2),
book(title3, author3),
book(title4, author1),
book(title5, author2),
...
I need to write a prolog query or rule to get titles grouped by the author (author1, author2...). I can't change order of facts in database.
For now I have only query looking like this:
book(T1, A), book(T2, A), T1 \= T2.
but it returns same thing few times
thanks in advance
This is too tough for me guys. It's for Jeremy!
I have two tables (although I can also envision needing to join a third table) and I want to sum one field and count rows, in the same, table while joining with another table and return the result in json format.
First of all, the data type field that needs to be summed, is numeric(10,2) and the data is inserted as params['amount'].to_f.
The tables are expense_projects which has the name of the project and the company id and expense_items which has the company_id, item and amount (to mention just the critical columns) - the "company_id" columns are disambiguated.
So, the following code:
expense_items = DB[:expense_projects].left_join(:expense_items, :expense_project_id => :project_id).where(:project_company_id => company_id).to_a.to_json
works fine but when I add
expense_total = expense_items.sum(:amount).to_f.to_json
I get an error message which says
TypeError - no implicit conversion of Symbol into Integer:
so, the first question is why and how can this be fixed?
Then I want to join the two tables and get all the project names form the left (first table) and sum amount and count items in the second table. I have tried
DB[:expense_projects].left_join(:expense_items, :expense_items_company_id => expense_projects_company_id).count(:item).sum(:amount).to_json
and variations of this, all of which fails.
I would like a result which gets all the project names (even if there are no expense entries and returns something like:
project item_count item_amount
pr 1 7 34.87
pr 2 0 0
and so on. How can this be achieved with one query returning the result in json format?
Many thanks, guys.
Figured it out, I hope this helps somebody else:
DB[:expense_projects___p].where(:project_company_id=>user_company_id).
left_join(:expense_items___i, :expense_project_id=>:project_id).
select_group(:p__project_name).
select_more{count(:i__item_id)}.
select_more{sum(:i__amount)}.to_a.to_json