Module: Sequel::ColumnsIntrospection

Defined in:
lib/sequel/extensions/columns_introspection.rb

Instance Method Summary collapse

Instance Method Details

#columns ⇒ Object

Attempt to guess the columns that will be returned if there are columns selected, in order to skip a database query to retrieve the columns. This should work with Symbols, SQL::Identifiers, SQL::QualifiedIdentifiers, and SQL::AliasedExpressions.



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# File 'lib/sequel/extensions/columns_introspection.rb', line 28

def columns
  return @columns if @columns
  return columns_without_introspection unless cols = opts[:select] and !cols.empty?
  probable_columns = cols.map{|c| probable_column_name(c)}
  if probable_columns.all?
    @columns = probable_columns
  else
    columns_without_introspection
  end
end