diff options
Diffstat (limited to 'activerecord/lib/active_record/associations/alias_tracker.rb')
-rw-r--r-- | activerecord/lib/active_record/associations/alias_tracker.rb | 91 |
1 files changed, 53 insertions, 38 deletions
diff --git a/activerecord/lib/active_record/associations/alias_tracker.rb b/activerecord/lib/active_record/associations/alias_tracker.rb index 0c23029981..2b7e4f28c5 100644 --- a/activerecord/lib/active_record/associations/alias_tracker.rb +++ b/activerecord/lib/active_record/associations/alias_tracker.rb @@ -5,71 +5,86 @@ module ActiveRecord # Keeps track of table aliases for ActiveRecord::Associations::ClassMethods::JoinDependency and # ActiveRecord::Associations::ThroughAssociationScope class AliasTracker # :nodoc: - attr_reader :aliases, :table_joins, :connection + attr_reader :aliases - # table_joins is an array of arel joins which might conflict with the aliases we assign here - def initialize(connection = Base.connection, table_joins = []) - @aliases = Hash.new { |h,k| h[k] = initial_count_for(k) } - @table_joins = table_joins - @connection = connection + def self.create(connection, initial_table, type_caster) + aliases = Hash.new(0) + aliases[initial_table] = 1 + new connection, aliases, type_caster end - def aliased_table_for(table_name, aliased_name = nil) - table_alias = aliased_name_for(table_name, aliased_name) - - if table_alias == table_name - Arel::Table.new(table_name) + def self.create_with_joins(connection, initial_table, joins, type_caster) + if joins.empty? + create(connection, initial_table, type_caster) else - Arel::Table.new(table_name).alias(table_alias) + aliases = Hash.new { |h, k| + h[k] = initial_count_for(connection, k, joins) + } + aliases[initial_table] = 1 + new connection, aliases, type_caster end end - def aliased_name_for(table_name, aliased_name = nil) - aliased_name ||= table_name + def self.initial_count_for(connection, name, table_joins) + # quoted_name should be downcased as some database adapters (Oracle) return quoted name in uppercase + quoted_name = connection.quote_table_name(name).downcase + counts = table_joins.map do |join| + if join.is_a?(Arel::Nodes::StringJoin) + # Table names + table aliases + join.left.downcase.scan( + /join(?:\s+\w+)?\s+(\S+\s+)?#{quoted_name}\son/ + ).size + elsif join.respond_to? :left + join.left.table_name == name ? 1 : 0 + else + # this branch is reached by two tests: + # + # activerecord/test/cases/associations/cascaded_eager_loading_test.rb:37 + # with :posts + # + # activerecord/test/cases/associations/eager_test.rb:1133 + # with :comments + # + 0 + end + end + + counts.sum + end + + # table_joins is an array of arel joins which might conflict with the aliases we assign here + def initialize(connection, aliases, type_caster) + @aliases = aliases + @connection = connection + @type_caster = type_caster + end + + def aliased_table_for(table_name, aliased_name) if aliases[table_name].zero? # If it's zero, we can have our table_name aliases[table_name] = 1 - table_name + Arel::Table.new(table_name, type_caster: @type_caster) else # Otherwise, we need to use an alias - aliased_name = connection.table_alias_for(aliased_name) + aliased_name = @connection.table_alias_for(aliased_name) # Update the count aliases[aliased_name] += 1 - if aliases[aliased_name] > 1 + table_alias = if aliases[aliased_name] > 1 "#{truncate(aliased_name)}_#{aliases[aliased_name]}" else aliased_name end + Arel::Table.new(table_name, type_caster: @type_caster).alias(table_alias) end end private - def initial_count_for(name) - return 0 if Arel::Table === table_joins - - # quoted_name should be downcased as some database adapters (Oracle) return quoted name in uppercase - quoted_name = connection.quote_table_name(name).downcase - - counts = table_joins.map do |join| - if join.is_a?(Arel::Nodes::StringJoin) - # Table names + table aliases - join.left.downcase.scan( - /join(?:\s+\w+)?\s+(\S+\s+)?#{quoted_name}\son/ - ).size - else - join.left.table_name == name ? 1 : 0 - end - end - - counts.sum - end - def truncate(name) - name.slice(0, connection.table_alias_length - 2) + name.slice(0, @connection.table_alias_length - 2) end end end |