In my controller I have
def services
#services = WorkQuote.group(:work_type_id).count
end
Which when ran in IRB:
irb(main):016:0> #services = WorkQuote.group(:work_type_id).count
(0.7ms) SELECT COUNT(*) AS count_all, work_type_id AS work_type_id FROM "work_quotes" GROUP BY "work_quotes"."work_type_id"
=> {1=>2, 3=>1}
Notice that the result is {1=>2, 3=>1}. In my controller I want to make a loop that builds a new array where the number to the left of the => is resolved by being inserted into this WorkType.find(number to the left of =>).worktype
So the new array would look like [Install=>2, Repair=>1} assuming that WorkType.find(1).worktype = Install and WorkType.find(3).worktype = Repair
Here is what worked for me although I am sure there is a cleaner way of doing this.
Basically grabbed each value with .each_key and pushed it into an array. Next I made a loop to grab the "count" which is the right side of each hash. Also in the loop I made an array that combined the resolved name of the WorkType id and the "count".
I realize that #printcount isn't needed in this situation.
#services = WorkQuote.group(:work_type_id).count
#printservices = []
#services.each_key {|key| #printservices.push(WorkType.find(key).worktype) }
#services = #services.to_a
#printcount = []
#printdisplay = []
iz = 0
while iz < #services.size
#printcount[iz] = #services[iz][1]
#printdisplay[iz] = [#printservices[iz], #services[iz][1]]
iz = iz + 1
end
Related
I need to be able to output the SQL UPDATES that would be generated by Rails, without actually running them or Saving the records. I will be outputting the SQL updates to a file instead.
Is there a way to do this in Rails, without using string interpolation?
Is it possible to do something like the following:
p = Post.where (something)
p.some_value = some_new_value
p.to_sql??? # how to generate the update statement
rather than:
"UPDATE TABLE SET field_1 = #{new_field} WHERE ID = " etc etc
Took from #R.F. Nelson and wrap it to a method. You could just calling to_update_sql with your model as the argument to get the SQL.
def to_update_sql(model)
return '' if model.changes.empty?
table = Arel::Table.new(model.class.table_name)
update_manager = Arel::UpdateManager.new(model.class)
update_manager.set(model.changes.map{|name, (_, val)| [table[name], val] })
.where(table[:id].eq(model.id))
.table(table)
return update_manager.to_sql
end
post = Post.first
post.some_value = xxxx
to_update_sql(post)
# => UPDATE `posts` SET `some_value` = xxx WHERE `posts`.`id` = 1
Taken from this post:
You can achieve this goal with AREL:
# Arel::InsertManager
table = Arel::Table.new(:users)
insert_manager = Arel::InsertManager.new
insert_manager.into(table)
insert_manager.insert([ [table[:first_name], 'Eddie'] ])
sql_transaction = insert_manager.to_sql
File.open('file_name.txt', 'w') do |file|
file.write(sql)
end
# Arel::UpdateManager
table = Arel::Table.new(:users)
update_manager = Arel::UpdateManager.new
update_manager.set([[table[:first_name], "Vedder"]]).where(table[:id].eq(1)).table(table)
sql_transaction = update_manager.to_sql
File.open('file_name.txt', 'w') do |file|
file.write(sql)
end
Here you can find all Arel managers, like delete_manager.rb, select_manager.rb and the others.
Good read: http://jpospisil.com/2014/06/16/the-definitive-guide-to-arel-the-sql-manager-for-ruby.html
I am trying to run following query through Rails query interface but unable to translate my logic. The query is
Select f.* from feeds f
Left join feed_items fi on fi.id = f.feedable_id
where
f.feedable_type in ('Homework', 'Datesheet')
and
(
(fi.assignable_type = 'Level' and assignable_id IN (1)) or
(fi.assignable_type = 'Student' and assignable_id IN (1)) or
(fi.assignable_type = 'Section' and assignable_id IN (1))
)
Scenario:
I receive following params hash in my action containing filters which will be added dynamically in my query
{"page"=>"1", "limit"=>"2", "type_filter"=>["Homework", "Datesheet"], "assignable_filter"=>{"Student"=>"[2]", "Section"=>"[1]", "Level"=>"[1]"}}
So far, what I have done is joining the tables and added where clause for type filter but not sure how to dynamically add assignable_filters. Here is my rails code, options are params in following code
def get_feeds(options)
base = Feed.includes(:feed_item)
base = add_type_filters base, options
base = add_assignable_filters base, options
format_response base, options
end
def add_type_filters(base, options)
type_filter = options[:type_filter]
if !type_filter.nil? and type_filter.length > 0
base = base.where('feedable_type IN (?)', options[:type_filter])
end
base
end
def add_assignable_filters(base, options)
assignable_filter = options[:assignable_filter]
if !assignable_filter.nil?
assignable_filter.each do |key, value|
# code for adding filters combined with or conditions
end
# wrap the or conditions and join them with an and in main where clause
end
base
end
P.S I am using rails 5
There was no straight forward way of building the query dynamically. I had to construct the where string to solve the problem. My current solution is
def get_feeds(options)
params_hash = {}
type_filters = add_type_filters options, params_hash
assignable_filters = add_assignable_filters options, params_hash
where = type_filters
where = where ? "#{where} and (#{assignable_filters})" : assignable_filters
base = Feed.eager_load(:feed_item).where(where, params_hash)
format_response base, options
end
def add_type_filters(options, params_hash)
type_filter = options[:type_filter]
type_filter_sql = nil
if !type_filter.nil? and type_filter.length > 0
type_filter_sql = 'feeds.feedable_type in (:type_filter)'
params_hash[:type_filter] = type_filter
end
type_filter_sql
end
def add_assignable_filters(options, params_hash)
assignable_filter_sql = []
assignable_filter = options[:assignable_filter]
if !assignable_filter.nil?
assignable_filter.each do |key, value|
assignable_filter_sql.push("(feed_items.assignable_type = '#{key}' and feed_items.assignable_id IN (:#{key}))")
params_hash[key.to_sym] = JSON.parse(value)
end
end
assignable_filter_sql.join(' or ')
end
Let's say i have two relation arrays of a user's daily buy and sell.
how do i iterate through both of them using .each and still let the the longer array run independently once the shorter one is exhaused. Below i want to find the ratio of someone's daily buys and sells. But can't get the ratio because it's always 1 as i'm iterating through the longer array once for each item of the shorter array.
users = User.all
ratios = Hash.new
users.each do |user|
if user.buys.count > 0 && user.sells.count > 0
ratios[user.name] = Hash.new
buy_array = []
sell_array = []
date = ""
daily_buy = user.buys.group_by(&:created_at)
daily_sell = user.sells.group_by(&:created_at)
daily_buy.each do |buy|
daily_sell.each do |sell|
if buy[0].to_date == sell[0].to_date
date = buy[0].to_date
buy_array << buy[1]
sell_array << sell[1]
end
end
end
ratio_hash[user.name][date] = (buy_array.length.round(2)/sell_array.length)
end
end
Thanks!
You could concat both arrays and get rid of duplicated elements by doing:
(a_array + b_array).uniq.each do |num|
# code goes here
end
Uniq method API
daily_buy = user.buys.group_by(&:created_at)
daily_sell = user.sells.group_by(&:created_at
buys_and_sells = daily_buy + daily_sell
totals = buys_and_sells.inject({}) do |hsh, transaction|
hsh['buys'] ||= 0;
hsh['sells'] ||= 0;
hsh['buys'] += 1 if transaction.is_a?(Buy)
hsh['sells'] += 1 if transaction.is_a?(Sell)
hsh
end
hsh['buys']/hsh['sells']
I think the above might do it...rather than collecting each thing in to separate arrays, concat them together, then run through each item in the combined array, increasing the count in the appropriate key of the hash returned by the inject.
In this case you can't loop them with each use for loop
this code will give you a hint
ar = [1,2,3,4,5]
br = [1,2,3]
array_l = (ar.length > br.length) ? ar.length : br.length
for i in 0..array_l
if ar[i] and br[i]
puts ar[i].to_s + " " + br[i].to_s
elsif ar[i]
puts ar[i].to_s
elsif br[i]
puts br[i].to_s
end
end
The real tactical question I am facing is all categories are set as 'default' therefore if I make options[:category] = 'default' it only adds the points that have no category. Therefore if i add points to cateogry 'arin' it will not be counted to the 'default' total. So I tried to grab all tables if NOT NULL or by category but it keeps grabbing the same amount for 'arin'.
default: 20
arin: 20
Should be total of 40 if category not supplied or at 'default', if params category 'arin' then it should be 20.
Can someone help me understand the concept behind the correct SQL to get the results I am looking for?
New to rails and SQL.
def self.top_scored(options = {})
options[:table_name] ||= :users
options[:since_date] ||= 4.months.ago
options[:end_date] ||= 1.month.from_now
options[:category] ||= nil
options[:limit] ||= 10
alias_id_column = "#{options[:table_name].to_s.singularize}_id"
if options[:table_name] == :sashes
sash_id_column = "#{options[:table_name]}.id"
else
sash_id_column = "#{options[:table_name]}.sash_id"
end
# MeritableModel - Sash -< Scores -< ScorePoints
sql_query = <<SQL
SELECT
#{options[:table_name]}.id AS #{alias_id_column},
SUM(num_points) as sum_points
FROM #{options[:table_name]}
LEFT JOIN merit_scores ON merit_scores.sash_id = #{sash_id_column}
LEFT JOIN merit_score_points ON merit_score_points.score_id = merit_scores.id
WHERE merit_score_points.created_at > '#{options[:since_date]}' AND merit_score_points.created_at < '#{options[:end_date]}' AND (merit_scores.category IS NOT NULL OR merit_scores.category = '#{options[:category]}')
GROUP BY #{options[:table_name]}.id, merit_scores.sash_id
ORDER BY sum_points DESC
LIMIT #{options[:limit]}
SQL
results = ActiveRecord::Base.connection.execute(sql_query)
results.map do |h|
h.keep_if { |k, v| (k == alias_id_column) || (k == 'sum_points') }
end
results
end
end
Seems no one answered and only down voted. Here is to anyone that questions this in the future. I figured out you can split sql statements and use an if statement in rails around the SQL.
sql_query = "SELECT
#{options[:table_name]}.id AS #{alias_id_column},
SUM(num_points) as sum_points
FROM #{options[:table_name]}
LEFT JOIN merit_scores ON merit_scores.sash_id = #{sash_id_column}
LEFT JOIN merit_score_points ON merit_score_points.score_id = merit_scores.id
WHERE merit_score_points.created_at > '#{options[:since_date]}' AND merit_score_points.created_at < '#{options[:end_date]}' "
if(options[:category] != nil)
sql_query += "AND merit_scores.category = \"#{options[:category]}\" "
end
sql_query += "GROUP BY #{options[:table_name]}.id, merit_scores.sash_id
ORDER BY sum_points DESC
LIMIT #{options[:limit]} "
results = ActiveRecord::Base.connection.execute(sql_query)
I am working on a script that is supposed to be writing a list of items to a hash, but for some reason its only placing the last item in the loop in the hash... I have been working on this script all day, so I am pretty sure its something I am just missing.
Here is the script
#mr = MediaRating.where("user_id = ?", session['user_credentials_id'])
#mr.each do |rating|
#m = Media.where("id = ?", rating.media_id)
#m.each do |m|
s = Profile.find_by_subscriber_id(m.subscriber_id)
#h_lang = Language.find_by_code(s.language)
#history = {m.title => #h_lang.english}
end
end
There are multiple records in the MediaRating table so I know it has to do something with how my loop is. Thanks in advance for the help!
Working code:
#mr = MediaRating.where("user_id = ?", session['user_credentials_id'])
#mr.each do |rating|
#m = Media.find(rating.media_id)
s = Profile.find_by_subscriber_id(#m.subscriber_id)
#h_lang = Language.find_by_code(s.language)
#history[#m.title] = #h_lang.english
end
In the last line, you are over-writing the entire #history hash instead of adding a new key/value pair to it. I'm guessing that isn't what you intended. Change this line:
#history = {m.title => #h_lang.english}
to this:
#history[m.title] = #h_lang.english