I have some query statements and I want to take the average by basically doing top_level_comment_count.fdiv(code_review_assigned_count).round(2)
Here are my 2 query statements:
top_level_comment_count = CrucibleComment.group(:user_id).where(parent_comment_id: nil).count
code_review_assigned_count = Reviewer.group(:user_id).count
Both of these return something that looks like this:
40=>5,
41=>1,
43=>4,
44=>10,
45=>2,
46=>13,
48=>7,
50=>7,
51=>6,
52=>5,
54=>7,
55=>41,
56=>2,
58=>21,
60=>7,
61=>8,
62=>3,
63=>1,
So, what I am wanting to do is if the :user_ids are the same, take the average.
My def currently looks like this:
def self.average_top_level_comments
a = CrucibleComment.group(:user_id).where(parent_comment_id: nil).count
b = Reviewer.group(:user_id).count
end
In other words I am wanting to do this statement:
return nil unless code_review_assigned_count && top_level_comment_count
top_level_comment_count.fdiv(code_review_assigned_count).round(2)
for a group of numbers. How can I do this?
For example:
id:40 => 5.0/3.3
id: 41 => 1/2.2
id: 43 => 4 /1.0
I would suggest using inject.
Something like:
division_result = top_level_comment_count.inject({}) do |result, item|
id = item.first
count = item.last
result[id] = count.to_f / code_review_assigned_count[id]
result
end
That will return a hash with the IDs as keys and the results of the division as the values.
Related
So I've got a table named Summaries, it looks like this
I need to get to sum the latest entries of TotalPieces based on CoveredDate and should be grouped by ServiceCode and queried by month
for example, ServiceCode 'A' has entries on 2020-01-01, 2020-01-02, 2020-01-03, 2020-01-31, 2020-02-01, 2020-02-28, 2020-02-29
and ServiceCode 'B' has entries on 2020-01-01, 2020-01-02, 2020-01-31, 2020-02-20, 2020-02-21,
i need to get the sum based on month, lastest entry on 'A' on January is on 2020-01-31, and 'B' has latest entry on 2020-01-31, I need to sum their 'TotalPieces', so I should get 25 + 25 = 50.
basically i need to do is
Get all the lastest entries based on CoveredDate and month/year
Sum the TotalPieces by ServiceCode
i got a working query, but this is just a workaround because i can't get it right on query.
int sum_totalpieces = 0;
foreach (var serviceCode in service_codes)
{
var totalpieces = _DbContext.ActiveSummaries.Where(acs =>
acs.CoveredDate.Date.Month == query_month
&& acs.CoveredDate.Date.Year == query_year
&& acs.service_codes == serviceCode
)
.OrderByDescending(obd => obd.CoveredDate)
.Take(1)
.Select(s => s.TotalPieces)
.ToList()
.FirstOrDefault();
sum_totalpieces += totalpieces;
}
the service_codes is just a List of string
If you guys could just get rid of the foreach block their and make it services_codes.Contains() on query, or another workaround to make the result faster that would be great. Thanks a lot.
This will do it, but I don't think it will translate to SQL and run at the server:
_DbContext.ActiveSummaries
.Where(b =>
b.CoveredDate >= new DateTime(2020,1,1) &&
b.CoveredDate < new DateTime(2020,2,1) &&
new [] { "A", "B" }.Contains(b.ServiceCode)
)
.GroupBy(g => g.ServiceCode)
.Sum(g => g.OrderByDescending(gb=> gb.CoveredDate).First().TotalPieces);
If you want to do it as a raw SQL for best performance it would look like:
SELECT SUM(totalpieces)
FROM
x
INNER JOIN
(
SELECT servicecode, MAX(covereddate) cd
FROM x
WHERE x.servicecode IN ('A','B') AND covereddate BETWEEN '2020-01-01' AND '2020-01-31'
)y ON x.servicecode=y.servicecode and x.covereddate = y.cd
I want to multiply a value of an specific column considering the user id.
Assume I have a table users with user 1 (id 1) and user 2 (id 2), and a table animals which has name and mensal_cost.
Ok, then I added two animals for user 1 (id 1) and 1 animal for user 2 (id 2)
I want to know how I can using ActiveRecord calculates the mensal_cost income after 3 months increasing the same base value, it means I have to multiply the actual value by 3.
I'm trying something like this:
Animal.where(user_id: ?).sum('3*mensal_cost')
Since I don't know how many users can exist, I must write a call which will list for each user id the amount after 3 months.
Ok, you nearly had it on your own - just the minor details can be like this:
user_ids = [id1, id2]
full_sum = 3 * Animal.where(:user_id => user_ids).sum(:mensal_cost)
Note: don't forget you can multiply by three after summing and it'll be the same as summing each one multiplied by 3 eg
(3 * 2) + (3 * 3) + (3 * 4) == 3 * (2 + 3 + 4)
or you can iterate through the users to get their individual sums like so:
mensal_sums = {}
user_ids = [id1, id2]
user_ids.each do |user_id|
mensal_sums[user_id] = 3 * Animal.where(:user_id => user_id).sum(:mensal_cost)
end
puts mensal_sums
=> {id1 => 63, id2 => 27}
EDIT
and one where you want the user name as well:
mensal_sums = {}
users = User.find([id1, id2])
users.each do |user|
mensal_sums[user.id] = {:user_name => user.name,
:sum => (3 * user.animals.sum(:mensal_cost)) }
end
puts mensal_sums
=> {id1 => {:user_name => "Bob Jones", :sum => 63},
id2 => {:user_name => "cJane Brown", :sum =>27}
}
I just figured out the solution:
Animal.group('user_id').sum('3*mensal_cost')
the group was the key :D
I am learning octave, and I have a comparison made like so:
ma = [1,2,3,4,5];
indices = ma > 3;
The conditions filter 'ma', and the var 'indices' prints the indices matching the conditions, which looks like:
[4, 5]
... but what I want is to use that result to return an array like this:
[0,0,0,4,5];
Is there a function for this?
You can do the following:
ma = [1,2,3,4,5];
ma(ma <= 3) = 0
Basically, just invert the condition and use it to set the values to zero.
I have three models Company, Deal and Slot. They are associated as Company has_many deals and Deal has_many slots. All the A company can be expired if all of its deals are expired. And a deal is expired when all of its slots are expired.
I have written a scope..
scope :expired,
lambda { |within|
self.select(
'DISTINCT companies.*'
).latest(within).joins(
:user =>{ :deals => :slots }
).where(
"companies.spam = false AND deals.deleted_at IS NULL
AND deals.spam = false AND slots.state = 1
OR slots.begin_at <= :time",
:time => Time.zone.now + SLOT_EXPIRY_MARGIN.minutes
)
}
The above scope does not seem right to me from what I am trying to achieve. I need companies with all of its slots for all the deals are either in state 1 or the begin_at is less than :time making it expired.
Thanks for having a look in advance.
AND has a higher precedence than OR in SQL so your where actually gets parsed like this:
(
companies.spam = false
and deals.deleted_at is null
and deals.spam = false
and slots.state = 1
)
or slots.begin_at <= :time
For example (trimmed a bit for brevity):
mysql> select 1 = 2 and 3 = 4 or 5 = 5;
+---+
| 1 |
+---+
mysql> select (1 = 2 and 3 = 4) or 5 = 5;
+---+
| 1 |
+---+
mysql> select 1 = 2 and (3 = 4 or 5 = 5);
+---+
| 0 |
+---+
Also, you might want to use a placeholder instead of the literal false in the SQL, that should make things easier if you want to switch databases (but of course, database portability is largely a myth so that's just a suggestion); you could also just use not in the SQL. Furthermore, using a class method is the preferred way to accept arguments for scopes. Using scoped instead of self is also a good idea in case other scopes are already in play but if you use a class method, you don't have to care.
If we fix the grouping in your SQL with some parentheses, use a placeholder for false, and switch to a class method:
def self.expired(within)
select('distinct companies.*').
latest(within).
joins(:user => { :deals => :slots }).
where(%q{
not companies.spam
and not deals.spam
and deals.deleted_at is null
and (slots.state = 1 or slots.begin_at <= :time)
}, :time => Time.zone.now + SLOT_EXPIRY_MARGIN.minutes)
end
You could also write it like this if you prefer little blobs of SQL rather than one big one:
def self.expired(within)
select('distinct companies.*').
latest(within).
joins(:user => { :deals => :slots }).
where('not companies.spam').
where('not deals.spam').
where('deals.deleted_at is null').
where('slots.state = 1 or slots.begin_at <= :time', :time => Time.zone.now + SLOT_EXPIRY_MARGIN.minutes)
end
This one also neatly sidesteps your "missing parentheses" problem.
UPDATE: Based on the discussion in the comments, I think you're after something like this:
def self.expired(within)
select('distinct companies.*').
latest(within).
joins(:user => :deals).
where('not companies.spam').
where('not deals.spam').
where('deals.deleted_at is null').
where(%q{
companies.id not in (
select company_id
from slots
where state = 1
and begin_at <= :time
group by company_id
having count(*) >= 10
)
}, :time => Time.zone.now + SLOT_EXPIRY_MARGIN.minutes
end
That bit of nastiness at the bottom grabs all the company IDs that have ten or more expired or used slots and then companies.id not in (...) excludes them from the final result set.
I have an object that looks like this one:
object =
title : 'an object'
properties :
attribute1 :
random_number: 2
attribute_values:
a: 10
b: 'irrelevant'
attribute2 :
random_number: 4
attribute_values:
a: 15
b: 'irrelevant'
some_random_stuff: 'random stuff'
I want to extract the sum of the 'a' values on attribute1 and attribute2.
What would be the best way to do this in Coffeescript?
(I have already found one way to do it but that just looks like Java-translated-to-coffee and I was hoping for a more elegant solution.)
Here is what I came up with (edited to be more generic based on comment):
sum_attributes = (x) =>
sum = 0
for name, value of object.properties
sum += value.attribute_values[x]
sum
alert sum_attributes('a') # 25
alert sum_attributes('b') # 0irrelevantirrelevant
So, that does what you want... but it probably doesn't do exactly what you want with strings.
You might want to pass in the accumulator seed, like sum_attributes 0, 'a' and sum_attributes '', 'b'
Brian's answer is good. But if you wanted to bring in a functional programming library like Underscore.js, you could write a more succinct version:
sum = (arr) -> _.reduce arr, ((memo, num) -> memo + num), 0
sum _.pluck(object.properties, 'a')
total = (attr.attribute_values.a for key, attr of obj.properties).reduce (a,b) -> a+b
or
sum = (arr) -> arr.reduce((a, b) -> a+b)
total = sum (attr.attribute_values.a for k, attr of obj.properties)