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−# This Source Code Form is subject to the terms of the Mozilla Public
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−# License, v. 2.0.  If a copy of the MPL was not distributed with this
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−# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
−#
+
−# Copyright 1997 - July 2008 CWI, August 2008 - 2020 MonetDB B.V.
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−
+
−# Models a MonetDB RecordSet
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−require 'time'
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−require 'date'
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−require 'ostruct'
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−
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−require "bigdecimal"
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−
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−require_relative 'MonetDBConnection'
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−
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−require 'logger'
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−
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−class MonetDBData
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−	@@DEBUG               = false
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−
+
−	def initialize(connection)
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−		@connection = connection
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−		@lang = @connection.lang
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−
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−		# Structure containing the header+results set for a fired Q_TABLE query
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−		@header = []
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−		@query  = {}
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−
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−		@record_set = []
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−		@index = 0 # Position of the last returned record
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−
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−
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−		@row_count = 0
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−		@row_offset = 10
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−		@row_index = Integer(MonetDBConnection::REPLY_SIZE)
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−	end
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−
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−	# Fire a query and return the server response
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−	def execute(q)
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−		# fire a query and get ready to receive the data
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−		@connection.send(format_query(q))
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−		data = @connection.receive
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−
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−		return if data == nil
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−
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−		record_set = "" # temporarily store retrieved rows
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−		record_set = receive_record_set(data)
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−
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−		if (@lang == MonetDBConnection::LANG_SQL)
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−			rows = receive_record_set(data)
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−			# the fired query is a SELECT; store and return the whole record set
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−			if @action == MonetDBConnection::Q_TABLE
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−				@header = parse_header_table(@header)
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−				@header.freeze
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−
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−				if @row_index.to_i < @row_count.to_i
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−					block_rows = ""
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−					while next_block
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−						data = @connection.receive
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−						block_rows += receive_record_set(data)
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−					end
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−					record_set += block_rows
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−				end
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−			end
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−
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−			# ruby string management seems to not properly understand the MSG_PROMPT escape character.
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−			# In order to avoid data loss the @record_set array is built once that all tuples have been retrieved
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−			@record_set = record_set.split("\t]\n")
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−
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−			if @record_set.length != @query['rows'].to_i
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−				raise MonetDBQueryError, "Warning: Query #{@query['id']} declared to result in #{@query['rows']} but #{@record_set.length} returned instead"
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−			end
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−		end
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−		@record_set.freeze
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−	end
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−
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−	# Returns the record set entries hashed by column name ordered by column position
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−	def fetch_all_as_column_hash
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−		columns = {}
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−		@header["columns_name"].each do |col_name|
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−			columns[col_name] = fetch_by_column_name(col_name)
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−		end
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−
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−		return columns
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−	end
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−
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−	# returns a record hash (i.e: { id: 1, name: "John Doe", age: 42 } )
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−	def fetch_hash
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−		return false if @index >= @query['rows'].to_i
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−
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−		record_hash = record_hash(parse_tuple(@record_set[@index]))
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−		@index += 1
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−		return record_hash
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−	end
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−
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−	# loops through all the hashes of the records and yields them to a given block
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−	def each_record_as_hash
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−		@record_set.each do |record|
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−			parsed_record = parse_tuple(record)
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−			yield(record_hash(parsed_record))
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−		end
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−	end
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−
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−	# Returns the values for the column 'field'
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−	def fetch_by_column_name(column_name="")
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−		position = @header["columns_order"].fetch(column_name)
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−
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−		column_values = []
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−		@record_set.each do |row|
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−			column_values << parse_tuple(row)[position]
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−		end
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−
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−		return column_values
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−	end
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−
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−	# fetches a single record, updates the iterator index
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−	def fetch
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−		return false if @index >= @query['rows'].to_i
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−
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−		result = parse_tuple(@record_set[@index])
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−		@index += 1
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−
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−		return result
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−	end
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−
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−	# resets the internal iterator index used by fetch and fetch_hash
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−	def reset_index
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−		@index = 0
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−	end
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−
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−	# loops through all records and yields to a given block parameter
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−	def each_record
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−		raise MonetDBDataError, "There is no record set currently available" unless @query['type'] == MonetDBConnection::Q_TABLE
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−		@record_set.each { |record| yield(parse_tuple(record)) }
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−	end
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−
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−	# Cursor method that returns all the records
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−	def fetch_all
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−		result = []
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−		each_record do |record|
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−			result.push(record)
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−		end
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−		return result
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−	end
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−
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−	# Returns the number of rows in the record set
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−	def num_rows
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−		return @query['rows'].to_i
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−	end
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−
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−	# Returns the number of fields in the record set
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−	def num_fields
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−		return @query['columns'].to_i
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−	end
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−
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−	# Returns the (ordered) name of the columns' tables in the record set
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−	def table_name_fields
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−		return @header['table_name']
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−	end
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−
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−	# Returns the (ordered) name of the columns in the record set
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−	def name_fields
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−		return @header['columns_name']
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−	end
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−
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−	# Returns the (ordered) name of the columns in the record set
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−	def type_fields
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−		return @header['columns_type']
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−	end
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−
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−	# ===================
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−    private
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−	# ===================
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−
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−	# store block of data, parse it and store it.
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−	def receive_record_set(response)
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−		rows = ""
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−		response.each_line do |row|
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−			case row[0]
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−			when MonetDBConnection::MSG_QUERY then parse_query(row)
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−			when MonetDBConnection::MSG_INFO then raise MonetDBQueryError, row
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−			when MonetDBConnection::MSG_SCHEMA_HEADER then @header << row
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−			when MonetDBConnection::MSG_TUPLE then rows += row
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−			when MonetDBConnection::MSG_PROMPT then return rows
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−			end
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−		end
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−		return rows # return an array of unparsed tuples
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−	end
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−
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−	def parse_query(row)
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−		case row[1]
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−		when MonetDBConnection::Q_TABLE
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−			@action = MonetDBConnection::Q_TABLE
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−			@query = parse_header_query(row)
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−			@query.freeze
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−			@row_count = @query['rows'].to_i #total number of rows in table
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−		when MonetDBConnection::Q_BLOCK
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−			@action = MonetDBConnection::Q_BLOCK # strip the block header from data
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−			@block = parse_header_query(row)
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−		when MonetDBConnection::Q_TRANSACTION
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−			@action = MonetDBConnection::Q_TRANSACTION
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−		when MonetDBConnection::Q_CREATE
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−			@action = MonetDBConnection::Q_CREATE
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−		end
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−	end
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−
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−	def record_hash(record)
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−		result = {}
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−
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−		@header["columns_name"].each do |column_name|
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−			position = @header["columns_order"].fetch(column_name)
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−			result[column_name] = record[position]
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−		end
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−
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−		return result
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−	end
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−
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−	def next_block
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−		if @row_index == @row_count
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−			return false
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−		else
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−			# The increment step is small to better deal with ruby socket's performance.
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−			# For larger values of the step performance drop;
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−			#
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−			@row_offset = [@row_offset, (@row_count - @row_index)].min
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−
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−			# export offset amount
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−			@connection.set_export(@query['id'], @row_index.to_s, @row_offset.to_s)
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−			@row_index += @row_offset
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−			@row_offset += 1
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−		end
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−		return true
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−
+
−	end
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−
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−	# Formats a query <i>string</i> so that it can be parsed by the server
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−	def format_query(q)
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−		if @lang == MonetDBConnection::LANG_SQL
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−			return "s" + q + "\n;"
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−		else
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−			raise LanguageNotSupported, @lang
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−		end
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−	end
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−
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−	# parse one tuple as returned from the server
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−	def parse_tuple(tuple)
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−		fields = []
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−		# remove trailing  "["
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−		tuple = tuple.gsub(/^\[\s+/,'')
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−		tuple.split(/,\t/).each_with_index do |field, index|
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−			field_value = convert_type(field, index)
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−			fields << field_value
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−		end
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−
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−		return fields.freeze
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−	end
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−
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−	# converts the given value the correct type
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−	def convert_type(value, index)
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−		return nil if "NULL" == value.upcase
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−		return case type_fields.values[index]
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−			   when "int", "tinyint", "smallint", "bigint", "hugeint" then value.to_i
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−			   when "double", "real", "decimal" then value.to_f
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−			   when "boolean" then value.downcase == true
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−			   when "date" then Date.parse(value)
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−			   when "time" then Time.parse(value, Time.new("2000-01-01"))
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−			   when "timestamp" then DateTime.parse(value)
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−			   when "timestamptz" then DateTime.parse(value)
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−			   else value.gsub(/\\/, '').gsub(/^"/,'').gsub(/"$/,'').gsub(/\"/, '')
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−			   end
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−	end
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−
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−	# Parses a query header and returns information about the query.
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−	def parse_header_query(row)
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−		type = row[1].chr
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−		if type == MonetDBConnection::Q_TABLE
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−			# Performing a SELECT: store information about the table size, query id, total number of records and returned.
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−			id = row.split(' ')[1]
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−			rows = row.split(' ')[2]
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−			columns = row.split(' ')[3]
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−			returned = row.split(' ')[4]
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−
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−			header = { "id" => id, "type" => type, "rows" => rows, "columns" => columns, "returned" => returned }
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−		elsif  type == MonetDBConnection::Q_BLOCK
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−			# processing block header
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−
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−			id = row.split(' ')[1]
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−			columns = row.split(' ')[2]
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−			remains = row.split(' ')[3]
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−			offset = row.split(' ')[4]
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−
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−			header = { "id" => id, "type" => type, "remains" => remains, "columns" => columns, "offset" => offset }
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−		else
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−			header = {"type" => type}
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−		end
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−
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−		return header.freeze
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−	end
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−
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−	# Parse escaped strings between double quotes
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−	def parse_header_table_values(line, start, stop, results)
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−		i = start
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−		inString = false
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−		escaped = false
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−
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−		until i == stop do
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−			case line[i]
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−			when '\\'
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−				escaped = !escaped
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−			when '"'
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−				if !inString
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−					inString = true
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−				elsif !escaped
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−					inString = false
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−				end
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−				escaped = false
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−			when ','
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−				if !inString # && line[i + 1] == '\t'
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−					if line[start] == '"' # Don't include the leading " in the column attribute
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−						start += 1
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−					end
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−					if line[i - 1] == '"'
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−						next_end = 2
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−					else
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−						next_end = 1
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−					end
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−					results.push(line[start..i - next_end])
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−					i += 1
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−					start = i + 1
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−				end
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−				escaped = false
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−			else
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−				escaped = false
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−			end
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−			i += 1
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−		end
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−		if line[start] == '"' # Don't include the leading " in the column attribute
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−			start += 1
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−		end
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−		if line[stop] == '"'
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−			next_end = 1
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−		else
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−			next_end = 0
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−		end
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−		results.push(line[start..stop - next_end])
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−	end
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−
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−	# Parses a Q_TABLE header and returns information about the schema.
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−	def parse_header_table(header_t)
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−		if @query["type"] == MonetDBConnection::Q_TABLE
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−			if header_t != nil
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−
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−				name_t = Array.new
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−				parse_header_table_values(header_t[0], 2, header_t[0].length - 15, name_t)
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−
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−				name_cols = Array.new
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−				parse_header_table_values(header_t[1], 2, header_t[1].length - 9, name_cols)
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−
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−				type_cols = { }
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−				type_cols_array = Array.new
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−				parse_header_table_values(header_t[2], 2, header_t[2].length - 9, type_cols_array)
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−				type_cols_array.each_with_index do |col, i|
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−					type_cols[name_cols[i]] = col
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−				end
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−
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−				length_cols = { }
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−				length_cols_array = Array.new
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−				parse_header_table_values(header_t[3], 2, header_t[3].length - 11, length_cols_array)
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−				length_cols_array.each_with_index do |col, i|
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−					length_cols[name_cols[i]] = col
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−				end
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−
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−				columns_order = {}
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−				name_cols.each_with_index do |col, i|
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−					columns_order[col] = i
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−				end
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−
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−				return {"table_name" => name_t, "columns_name" => name_cols, "columns_type" => type_cols,
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−						"columns_length" => length_cols, "columns_order" => columns_order}.freeze
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−			end
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−		end
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−	end
+
−end