1# frozen_string_literal: true
 2
 3require "delegate"
 4
 5class Postgres < SimpleDelegator
 6	def self.connect(**kwargs)
 7		new(PG::EM::ConnectionPool.new(**kwargs) { |conn|
 8			conn.type_map_for_results = PG::BasicTypeMapForResults.new(conn)
 9			conn.type_map_for_queries = PG::BasicTypeMapForQueries.new(conn)
10		})
11	end
12
13	def query_one(sql, *args, field_names_as: :symbol, default: nil)
14		query_defer(sql, args).then do |rows|
15			rows.field_names_as(field_names_as)&.first || default
16		end
17	end
18
19	def transaction(*args)
20		super(*args) do |db|
21			yield self.class.new(db)
22		end
23	end
24end