Module: ActiveRecord::ConnectionAdapters::ClickHouse::RelationDictionaries

Defined in:
lib/active_record/connection_adapters/clickhouse/querying.rb

Overview

Projects a dictionary lookup alongside the row — dictGet replaces the dimension JOIN of a star schema. Dictionary/attribute names travel as quoted string literals; only the alias needs identifier validation.

Instance Method Summary collapse

Instance Method Details

#dict_get(dictionary, attribute, key:, as: nil, default: nil) ⇒ Object 



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# File 'lib/active_record/connection_adapters/clickhouse/querying.rb', line 211

def dict_get(dictionary, attribute, key:, as: nil, default: nil)
  spawn.dict_get!(dictionary, attribute, key: key, as: as, default: default)
end

#dict_get!(dictionary, attribute, key:, as: nil, default: nil) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/active_record/connection_adapters/clickhouse/querying.rb', line 215

def dict_get!(dictionary, attribute, key:, as: nil, default: nil)
  alias_name = (as || attribute).to_s
  raise ArgumentError, "dict_get alias must be an identifier" unless
    RelationWindowing::WINDOW_IDENTIFIER.match?(alias_name)

  self.select_values += [klass.arel_table[::Arel.star]] if select_values.empty?
  self.select_values += [::Arel::Nodes::As.new(dict_get_node(dictionary, attribute, key, default),
                                               ::Arel.sql(alias_name))]
  self
end