diff options
Diffstat (limited to 'activerecord/lib/active_record/relation/finder_methods.rb')
| -rw-r--r-- | activerecord/lib/active_record/relation/finder_methods.rb | 198 |
1 files changed, 165 insertions, 33 deletions
diff --git a/activerecord/lib/active_record/relation/finder_methods.rb b/activerecord/lib/active_record/relation/finder_methods.rb index 4984dbd277..088bc203b7 100644 --- a/activerecord/lib/active_record/relation/finder_methods.rb +++ b/activerecord/lib/active_record/relation/finder_methods.rb @@ -1,3 +1,6 @@ +require 'active_support/deprecation' +require 'active_support/core_ext/string/filters' + module ActiveRecord module FinderMethods ONE_AS_ONE = '1 AS one' @@ -63,7 +66,7 @@ module ActiveRecord # # returns an Array of the required fields, available since Rails 3.1. def find(*args) if block_given? - to_a.find { |*block_args| yield(*block_args) } + to_a.find(*args) { |*block_args| yield(*block_args) } else find_with_ids(*args) end @@ -79,12 +82,16 @@ module ActiveRecord # Post.find_by "published_at < ?", 2.weeks.ago def find_by(*args) where(*args).take + rescue RangeError + nil end # Like <tt>find_by</tt>, except that if no record is found, raises # an <tt>ActiveRecord::RecordNotFound</tt> error. def find_by!(*args) where(*args).take! + rescue RangeError + raise RecordNotFound, "Couldn't find #{@klass.name} with an out of range value" end # Gives a record (or N records if a parameter is supplied) without any implied @@ -101,7 +108,7 @@ module ActiveRecord # Same as +take+ but raises <tt>ActiveRecord::RecordNotFound</tt> if no record # is found. Note that <tt>take!</tt> accepts no arguments. def take! - take or raise RecordNotFound + take or raise RecordNotFound.new("Couldn't find #{@klass.name} with [#{arel.where_sql(@klass.arel_engine)}]") end # Find the first record (or first N records if a parameter is supplied). @@ -127,16 +134,16 @@ module ActiveRecord # def first(limit = nil) if limit - find_first_with_limit(limit) + find_nth_with_limit(offset_index, limit) else - find_first + find_nth(0, offset_index) end end # Same as +first+ but raises <tt>ActiveRecord::RecordNotFound</tt> if no record # is found. Note that <tt>first!</tt> accepts no arguments. def first! - first or raise RecordNotFound + find_nth! 0 end # Find the last record (or last N records if a parameter is supplied). @@ -169,7 +176,87 @@ module ActiveRecord # Same as +last+ but raises <tt>ActiveRecord::RecordNotFound</tt> if no record # is found. Note that <tt>last!</tt> accepts no arguments. def last! - last or raise RecordNotFound + last or raise RecordNotFound.new("Couldn't find #{@klass.name} with [#{arel.where_sql(@klass.arel_engine)}]") + end + + # Find the second record. + # If no order is defined it will order by primary key. + # + # Person.second # returns the second object fetched by SELECT * FROM people + # Person.offset(3).second # returns the second object from OFFSET 3 (which is OFFSET 4) + # Person.where(["user_name = :u", { u: user_name }]).second + def second + find_nth(1, offset_index) + end + + # Same as +second+ but raises <tt>ActiveRecord::RecordNotFound</tt> if no record + # is found. + def second! + find_nth! 1 + end + + # Find the third record. + # If no order is defined it will order by primary key. + # + # Person.third # returns the third object fetched by SELECT * FROM people + # Person.offset(3).third # returns the third object from OFFSET 3 (which is OFFSET 5) + # Person.where(["user_name = :u", { u: user_name }]).third + def third + find_nth(2, offset_index) + end + + # Same as +third+ but raises <tt>ActiveRecord::RecordNotFound</tt> if no record + # is found. + def third! + find_nth! 2 + end + + # Find the fourth record. + # If no order is defined it will order by primary key. + # + # Person.fourth # returns the fourth object fetched by SELECT * FROM people + # Person.offset(3).fourth # returns the fourth object from OFFSET 3 (which is OFFSET 6) + # Person.where(["user_name = :u", { u: user_name }]).fourth + def fourth + find_nth(3, offset_index) + end + + # Same as +fourth+ but raises <tt>ActiveRecord::RecordNotFound</tt> if no record + # is found. + def fourth! + find_nth! 3 + end + + # Find the fifth record. + # If no order is defined it will order by primary key. + # + # Person.fifth # returns the fifth object fetched by SELECT * FROM people + # Person.offset(3).fifth # returns the fifth object from OFFSET 3 (which is OFFSET 7) + # Person.where(["user_name = :u", { u: user_name }]).fifth + def fifth + find_nth(4, offset_index) + end + + # Same as +fifth+ but raises <tt>ActiveRecord::RecordNotFound</tt> if no record + # is found. + def fifth! + find_nth! 4 + end + + # Find the forty-second record. Also known as accessing "the reddit". + # If no order is defined it will order by primary key. + # + # Person.forty_two # returns the forty-second object fetched by SELECT * FROM people + # Person.offset(3).forty_two # returns the forty-second object from OFFSET 3 (which is OFFSET 44) + # Person.where(["user_name = :u", { u: user_name }]).forty_two + def forty_two + find_nth(41, offset_index) + end + + # Same as +forty_two+ but raises <tt>ActiveRecord::RecordNotFound</tt> if no record + # is found. + def forty_two! + find_nth! 41 end # Returns +true+ if a record exists in the table that matches the +id+ or @@ -200,7 +287,14 @@ module ActiveRecord # Person.exists?(false) # Person.exists? def exists?(conditions = :none) - conditions = conditions.id if Base === conditions + if Base === conditions + conditions = conditions.id + ActiveSupport::Deprecation.warn(<<-MSG.squish) + You are passing an instance of ActiveRecord::Base to `exists?`. + Please pass the id of the object by calling `.id` + MSG + end + return false if !conditions relation = apply_join_dependency(self, construct_join_dependency) @@ -212,10 +306,12 @@ module ActiveRecord when Array, Hash relation = relation.where(conditions) else - relation = relation.where(table[primary_key].eq(conditions)) if conditions != :none + unless conditions == :none + relation = where(primary_key => conditions) + end end - connection.select_value(relation, "#{name} Exists", relation.bind_values) ? true : false + connection.select_value(relation, "#{name} Exists", relation.arel.bind_values + relation.bind_values) ? true : false end # This method is called whenever no records are found with either a single @@ -227,13 +323,13 @@ module ActiveRecord # the expected number of results should be provided in the +expected_size+ # argument. def raise_record_not_found_exception!(ids, result_size, expected_size) #:nodoc: - conditions = arel.where_sql + conditions = arel.where_sql(@klass.arel_engine) conditions = " [#{conditions}]" if conditions if Array(ids).size == 1 - error = "Couldn't find #{@klass.name} with #{primary_key}=#{ids}#{conditions}" + error = "Couldn't find #{@klass.name} with '#{primary_key}'=#{ids}#{conditions}" else - error = "Couldn't find all #{@klass.name.pluralize} with IDs " + error = "Couldn't find all #{@klass.name.pluralize} with '#{primary_key}': " error << "(#{ids.join(", ")})#{conditions} (found #{result_size} results, but was looking for #{expected_size})" end @@ -242,8 +338,21 @@ module ActiveRecord private + def offset_index + offset_value || 0 + end + def find_with_associations - join_dependency = construct_join_dependency + # NOTE: the JoinDependency constructed here needs to know about + # any joins already present in `self`, so pass them in + # + # failing to do so means that in cases like activerecord/test/cases/associations/inner_join_association_test.rb:136 + # incorrect SQL is generated. In that case, the join dependency for + # SpecialCategorizations is constructed without knowledge of the + # preexisting join in joins_values to categorizations (by way of + # the `has_many :through` for categories). + # + join_dependency = construct_join_dependency(joins_values) aliases = join_dependency.aliases relation = select aliases.columns @@ -255,7 +364,8 @@ module ActiveRecord if ActiveRecord::NullRelation === relation [] else - rows = connection.select_all(relation.arel, 'SQL', relation.bind_values.dup) + arel = relation.arel + rows = connection.select_all(arel, 'SQL', arel.bind_values + relation.bind_values) join_dependency.instantiate(rows, aliases) end end @@ -267,7 +377,15 @@ module ActiveRecord end def construct_relation_for_association_calculations - apply_join_dependency(self, construct_join_dependency(arel.froms.first)) + from = arel.froms.first + if Arel::Table === from + apply_join_dependency(self, construct_join_dependency) + else + # FIXME: as far as I can tell, `from` will always be an Arel::Table. + # There are no tests that test this branch, but presumably it's + # possible for `from` to be a list? + apply_join_dependency(self, construct_join_dependency(from)) + end end def apply_join_dependency(relation, join_dependency) @@ -279,7 +397,7 @@ module ActiveRecord else if relation.limit_value limited_ids = limited_ids_for(relation) - limited_ids.empty? ? relation.none! : relation.where!(table[primary_key].in(limited_ids)) + limited_ids.empty? ? relation.none! : relation.where!(primary_key => limited_ids) end relation.except(:limit, :offset) end @@ -290,13 +408,14 @@ module ActiveRecord "#{quoted_table_name}.#{quoted_primary_key}", relation.order_values) relation = relation.except(:select).select(values).distinct! + arel = relation.arel - id_rows = @klass.connection.select_all(relation.arel, 'SQL', relation.bind_values) + id_rows = @klass.connection.select_all(arel, 'SQL', arel.bind_values + relation.bind_values) id_rows.map {|row| row[primary_key]} end def using_limitable_reflections?(reflections) - reflections.none? { |r| r.collection? } + reflections.none?(&:collection?) end protected @@ -318,15 +437,20 @@ module ActiveRecord else find_some(ids) end + rescue RangeError + raise RecordNotFound, "Couldn't find #{@klass.name} with an out of range ID" end def find_one(id) - id = id.id if ActiveRecord::Base === id + if ActiveRecord::Base === id + id = id.id + ActiveSupport::Deprecation.warn(<<-MSG.squish) + You are passing an instance of ActiveRecord::Base to `find`. + Please pass the id of the object by calling `.id` + MSG + end - column = columns_hash[primary_key] - substitute = connection.substitute_at(column, bind_values.length) - relation = where(table[primary_key].eq(substitute)) - relation.bind_values += [[column, id]] + relation = where(primary_key => id) record = relation.take raise_record_not_found_exception!(id, 0, 1) unless record @@ -335,7 +459,7 @@ module ActiveRecord end def find_some(ids) - result = where(table[primary_key].in(ids)).to_a + result = where(primary_key => ids).to_a expected_size = if limit_value && ids.size > limit_value @@ -364,20 +488,28 @@ module ActiveRecord end end - def find_first + def find_nth(index, offset) if loaded? - @records.first + @records[index] else - @first ||= find_first_with_limit(1).first + offset += index + @offsets[offset] ||= find_nth_with_limit(offset, 1).first end end - def find_first_with_limit(limit) - if order_values.empty? && primary_key - order(arel_table[primary_key].asc).limit(limit).to_a - else - limit(limit).to_a - end + def find_nth!(index) + find_nth(index, offset_index) or raise RecordNotFound.new("Couldn't find #{@klass.name} with [#{arel.where_sql(@klass.arel_engine)}]") + end + + def find_nth_with_limit(offset, limit) + relation = if order_values.empty? && primary_key + order(arel_table[primary_key].asc) + else + self + end + + relation = relation.offset(offset) unless offset.zero? + relation.limit(limit).to_a end def find_last |