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author | Jon Leighton <j@jonathanleighton.com> | 2012-04-13 19:25:51 +0100 |
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committer | Jon Leighton <j@jonathanleighton.com> | 2012-04-13 19:25:51 +0100 |
commit | 5aea01a610c2ef7fa576d39d40a5a25bcb9f6ed4 (patch) | |
tree | 59bb25bf0bed173e5867ca6243c1ceaebfaee979 /activerecord | |
parent | d961f490ff1624b7c24a69d546a613768906f05c (diff) | |
download | rails-5aea01a610c2ef7fa576d39d40a5a25bcb9f6ed4.tar.gz rails-5aea01a610c2ef7fa576d39d40a5a25bcb9f6ed4.tar.bz2 rails-5aea01a610c2ef7fa576d39d40a5a25bcb9f6ed4.zip |
extract deprecated #calculate code
Diffstat (limited to 'activerecord')
-rw-r--r-- | activerecord/lib/active_record/relation/calculations.rb | 108 |
1 files changed, 25 insertions, 83 deletions
diff --git a/activerecord/lib/active_record/relation/calculations.rb b/activerecord/lib/active_record/relation/calculations.rb index 6bb2c7af81..db894c8aa9 100644 --- a/activerecord/lib/active_record/relation/calculations.rb +++ b/activerecord/lib/active_record/relation/calculations.rb @@ -3,56 +3,19 @@ require 'active_support/core_ext/object/try' module ActiveRecord module Calculations - # Count operates using three different approaches. + # Count the records. # - # * Count all: By not passing any parameters to count, it will return a count of all the rows for the model. - # * Count using column: By passing a column name to count, it will return a count of all the - # rows for the model with supplied column present. - # * Count using options will find the row count matched by the options used. + # Person.count + # # => the total count of all people # - # The third approach, count using options, accepts an option hash as the only parameter. The options are: + # Person.count(:age) + # # => returns the total count of all people whose age is present in database # - # * <tt>:conditions</tt>: An SQL fragment like "administrator = 1" or [ "user_name = ?", username ]. - # See conditions in the intro to ActiveRecord::Base. - # * <tt>:joins</tt>: Either an SQL fragment for additional joins like "LEFT JOIN comments ON comments.post_id = id" - # (rarely needed) or named associations in the same form used for the <tt>:include</tt> option, which will - # perform an INNER JOIN on the associated table(s). If the value is a string, then the records - # will be returned read-only since they will have attributes that do not correspond to the table's columns. - # Pass <tt>:readonly => false</tt> to override. - # * <tt>:include</tt>: Named associations that should be loaded alongside using LEFT OUTER JOINs. - # The symbols named refer to already defined associations. When using named associations, count - # returns the number of DISTINCT items for the model you're counting. - # See eager loading under Associations. - # * <tt>:order</tt>: An SQL fragment like "created_at DESC, name" (really only used with GROUP BY calculations). - # * <tt>:group</tt>: An attribute name by which the result should be grouped. Uses the GROUP BY SQL-clause. - # * <tt>:select</tt>: By default, this is * as in SELECT * FROM, but can be changed if you, for example, - # want to do a join but not include the joined columns. - # * <tt>:distinct</tt>: Set this to true to make this a distinct calculation, such as - # SELECT COUNT(DISTINCT posts.id) ... - # * <tt>:from</tt> - By default, this is the table name of the class, but can be changed to an - # alternate table name (or even the name of a database view). + # Person.count(:all) + # # => performs a COUNT(*) (:all is an alias for '*') # - # Examples for counting all: - # Person.count # returns the total count of all people - # - # Examples for counting by column: - # Person.count(:age) # returns the total count of all people whose age is present in database - # - # Examples for count with options: - # Person.count(:conditions => "age > 26") - # - # # because of the named association, it finds the DISTINCT count using LEFT OUTER JOIN. - # Person.count(:conditions => "age > 26 AND job.salary > 60000", :include => :job) - # - # # finds the number of rows matching the conditions and joins. - # Person.count(:conditions => "age > 26 AND job.salary > 60000", - # :joins => "LEFT JOIN jobs on jobs.person_id = person.id") - # - # Person.count('id', :conditions => "age > 26") # Performs a COUNT(id) - # Person.count(:all, :conditions => "age > 26") # Performs a COUNT(*) (:all is an alias for '*') - # - # Note: <tt>Person.count(:all)</tt> will not work because it will use <tt>:all</tt> as the condition. - # Use Person.count instead. + # Person.count(:age, distinct: true) + # # => counts the number of different age values def count(column_name = nil, options = {}) column_name, options = nil, column_name if column_name.is_a?(Hash) calculate(:count, column_name, options) @@ -98,21 +61,22 @@ module ActiveRecord end # This calculates aggregate values in the given column. Methods for count, sum, average, - # minimum, and maximum have been added as shortcuts. Options such as <tt>:conditions</tt>, - # <tt>:order</tt>, <tt>:group</tt>, <tt>:having</tt>, and <tt>:joins</tt> can be passed to customize the query. + # minimum, and maximum have been added as shortcuts. # # There are two basic forms of output: + # # * Single aggregate value: The single value is type cast to Fixnum for COUNT, Float # for AVG, and the given column's type for everything else. - # * Grouped values: This returns an ordered hash of the values and groups them by the - # <tt>:group</tt> option. It takes either a column name, or the name of a belongs_to association. # - # values = Person.maximum(:age, :group => 'last_name') + # * Grouped values: This returns an ordered hash of the values and groups them. It + # takes either a column name, or the name of a belongs_to association. + # + # values = Person.group('last_name').maximum(:age) # puts values["Drake"] # => 43 # # drake = Family.find_by_last_name('Drake') - # values = Person.maximum(:age, :group => :family) # Person belongs_to :family + # values = Person.group(:family).maximum(:age) # Person belongs_to :family # puts values[drake] # => 43 # @@ -120,47 +84,25 @@ module ActiveRecord # ... # end # - # Options: - # * <tt>:conditions</tt> - An SQL fragment like "administrator = 1" or [ "user_name = ?", username ]. - # See conditions in the intro to ActiveRecord::Base. - # * <tt>:include</tt>: Eager loading, see Associations for details. Since calculations don't load anything, - # the purpose of this is to access fields on joined tables in your conditions, order, or group clauses. - # * <tt>:joins</tt> - An SQL fragment for additional joins like "LEFT JOIN comments ON comments.post_id = id". - # (Rarely needed). - # The records will be returned read-only since they will have attributes that do not correspond to the - # table's columns. - # * <tt>:order</tt> - An SQL fragment like "created_at DESC, name" (really only used with GROUP BY calculations). - # * <tt>:group</tt> - An attribute name by which the result should be grouped. Uses the GROUP BY SQL-clause. - # * <tt>:select</tt> - By default, this is * as in SELECT * FROM, but can be changed if you for example - # want to do a join, but not include the joined columns. - # * <tt>:distinct</tt> - Set this to true to make this a distinct calculation, such as - # SELECT COUNT(DISTINCT posts.id) ... - # # Examples: # Person.calculate(:count, :all) # The same as Person.count # Person.average(:age) # SELECT AVG(age) FROM people... - # Person.minimum(:age, :conditions => ['last_name != ?', 'Drake']) # Selects the minimum age for - # # everyone with a last name other than 'Drake' # # # Selects the minimum age for any family without any minors - # Person.minimum(:age, :having => 'min(age) > 17', :group => :last_name) + # Person.group(:last_name).having("min(age) > 17").minimum(:age) # # Person.sum("2 * age") def calculate(operation, column_name, options = {}) - if options.except(:distinct).present? - apply_finder_options(options.except(:distinct)).calculate(operation, column_name, :distinct => options[:distinct]) - else - relation = with_default_scope - - if relation.equal?(self) - if eager_loading? || (includes_values.present? && references_eager_loaded_tables?) - construct_relation_for_association_calculations.calculate(operation, column_name, options) - else - perform_calculation(operation, column_name, options) - end + relation = with_default_scope + + if relation.equal?(self) + if eager_loading? || (includes_values.present? && references_eager_loaded_tables?) + construct_relation_for_association_calculations.calculate(operation, column_name, options) else - relation.calculate(operation, column_name, options) + perform_calculation(operation, column_name, options) end + else + relation.calculate(operation, column_name, options) end rescue ThrowResult 0 |