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c083ce6dd2
Attempting to reduce the number of places that care about the details of how type casting occurs. We remove the type casting of the primary key in `JoinDependecy`, rather than encapsulating it. It was originally added for consistency with40898c8c19 (diff-06059df8d3dee3101718fb2c01151ad0R211), but that conditional was later removed ind7ddaa530f. What is important is that the same row twice will have the same value for the primary key, which it will.
127 lines
3.1 KiB
Ruby
127 lines
3.1 KiB
Ruby
module ActiveRecord
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###
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# This class encapsulates a Result returned from calling +exec_query+ on any
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# database connection adapter. For example:
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#
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# result = ActiveRecord::Base.connection.exec_query('SELECT id, title, body FROM posts')
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# result # => #<ActiveRecord::Result:0xdeadbeef>
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#
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# # Get the column names of the result:
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# result.columns
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# # => ["id", "title", "body"]
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#
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# # Get the record values of the result:
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# result.rows
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# # => [[1, "title_1", "body_1"],
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# [2, "title_2", "body_2"],
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# ...
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# ]
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#
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# # Get an array of hashes representing the result (column => value):
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# result.to_hash
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# # => [{"id" => 1, "title" => "title_1", "body" => "body_1"},
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# {"id" => 2, "title" => "title_2", "body" => "body_2"},
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# ...
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# ]
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#
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# # ActiveRecord::Result also includes Enumerable.
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# result.each do |row|
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# puts row['title'] + " " + row['body']
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# end
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class Result
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include Enumerable
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IDENTITY_TYPE = Type::Value.new # :nodoc:
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attr_reader :columns, :rows, :column_types
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def initialize(columns, rows, column_types = {})
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@columns = columns
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@rows = rows
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@hash_rows = nil
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@column_types = column_types
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end
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def each
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if block_given?
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hash_rows.each { |row| yield row }
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else
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hash_rows.to_enum { @rows.size }
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end
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end
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def to_hash
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hash_rows
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end
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alias :map! :map
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alias :collect! :map
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# Returns true if there are no records.
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def empty?
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rows.empty?
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end
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def to_ary
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hash_rows
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end
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def [](idx)
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hash_rows[idx]
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end
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def last
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hash_rows.last
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end
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def cast_values(type_overrides = {}) # :nodoc:
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types = columns.map { |name| column_type(name, type_overrides) }
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result = rows.map do |values|
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types.zip(values).map { |type, value| type.type_cast_from_database(value) }
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end
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columns.one? ? result.map!(&:first) : result
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end
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def initialize_copy(other)
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@columns = columns.dup
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@rows = rows.dup
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@column_types = column_types.dup
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@hash_rows = nil
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end
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private
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def column_type(name, type_overrides = {})
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type_overrides.fetch(name) do
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column_types.fetch(name, IDENTITY_TYPE)
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end
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end
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def hash_rows
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@hash_rows ||=
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begin
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# We freeze the strings to prevent them getting duped when
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# used as keys in ActiveRecord::Base's @attributes hash
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columns = @columns.map { |c| c.dup.freeze }
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@rows.map { |row|
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# In the past we used Hash[columns.zip(row)]
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# though elegant, the verbose way is much more efficient
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# both time and memory wise cause it avoids a big array allocation
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# this method is called a lot and needs to be micro optimised
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hash = {}
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index = 0
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length = columns.length
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while index < length
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hash[columns[index]] = row[index]
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index += 1
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end
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hash
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}
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end
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end
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end
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end
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