gitlab-org--gitlab-foss/lib/gitlab/pagination/keyset/in_operator_optimization/column_data.rb

53 lines
1.5 KiB
Ruby

# frozen_string_literal: true
module Gitlab
module Pagination
module Keyset
module InOperatorOptimization
# This class is used for wrapping an Arel column with
# convenient helper methods in order to make the query
# building for the InOperatorOptimization a bit cleaner.
class ColumnData
attr_reader :original_column_name, :as, :arel_table
# column - name of the DB column
# as - custom alias for the column
# arel_table - relation where the column is located
def initialize(column, as, arel_table)
@original_column_name = column
@as = as.to_s
@arel_table = arel_table
end
# Generates: `issues.name AS my_alias`
def projection
arel_column.as(as)
end
# Generates: issues.name`
def arel_column
arel_table[original_column_name]
end
# overridden in OrderByColumnData class
alias_method :column_expression, :arel_column
# Generates: `issues.my_alias`
def arel_column_as
arel_table[as]
end
def array_aggregated_column_name
"#{arel_table.name}_#{original_column_name}_array"
end
# Generates: SELECT ARRAY_AGG(...) AS issues_name_array
def array_aggregated_column
Arel::Nodes::NamedFunction.new('ARRAY_AGG', [column_expression]).as(array_aggregated_column_name)
end
end
end
end
end
end