require 'active_record/connection_adapters/abstract_mysql_adapter'
gem 'mysql2', '~> 0.3.13'
require 'mysql2'
module ActiveRecord
module ConnectionHandling # :nodoc:
# Establishes a connection to the database that's used by all Active Record objects.
def mysql2_connection(config)
config = config.symbolize_keys
config[:username] = 'root' if config[:username].nil?
if Mysql2::Client.const_defined? :FOUND_ROWS
config[:flags] = Mysql2::Client::FOUND_ROWS
end
client = Mysql2::Client.new(config)
options = [config[:host], config[:username], config[:password], config[:database], config[:port], config[:socket], 0]
ConnectionAdapters::Mysql2Adapter.new(client, logger, options, config)
rescue Mysql2::Error => error
if error.message.include?("Unknown database")
raise ActiveRecord::NoDatabaseError.new(error.message, error)
else
raise
end
end
end
module ConnectionAdapters
class Mysql2Adapter < AbstractMysqlAdapter
class Column < AbstractMysqlAdapter::Column # :nodoc:
def adapter
Mysql2Adapter
end
end
ADAPTER_NAME = 'Mysql2'
def initialize(connection, logger, connection_options, config)
super
@visitor = BindSubstitution.new self
configure_connection
end
def cacheable_query(arel)
ActiveRecord::StatementCache.partial_query visitor, arel.ast
end
MAX_INDEX_LENGTH_FOR_UTF8MB4 = 191
def initialize_schema_migrations_table
if @config[:encoding] == 'utf8mb4'
ActiveRecord::SchemaMigration.create_table(MAX_INDEX_LENGTH_FOR_UTF8MB4)
else
ActiveRecord::SchemaMigration.create_table
end
end
def supports_explain?
true
end
# HELPER METHODS ===========================================
def each_hash(result) # :nodoc:
if block_given?
result.each(:as => :hash, :symbolize_keys => true) do |row|
yield row
end
else
to_enum(:each_hash, result)
end
end
def new_column(field, default, type, null, collation, extra = "") # :nodoc:
Column.new(field, default, type, null, collation, strict_mode?, extra)
end
def error_number(exception)
exception.error_number if exception.respond_to?(:error_number)
end
# QUOTING ==================================================
def quote_string(string)
@connection.escape(string)
end
def quoted_date(value)
if value.acts_like?(:time) && value.respond_to?(:usec)
"#{super}.#{sprintf("%06d", value.usec)}"
else
super
end
end
# CONNECTION MANAGEMENT ====================================
def active?
return false unless @connection
@connection.ping
end
def reconnect!
super
disconnect!
connect
end
alias :reset! :reconnect!
# Disconnects from the database if already connected.
# Otherwise, this method does nothing.
def disconnect!
super
unless @connection.nil?
@connection.close
@connection = nil
end
end
# DATABASE STATEMENTS ======================================
def explain(arel, binds = [])
sql = "EXPLAIN #{to_sql(arel, binds.dup)}"
start = Time.now
result = exec_query(sql, 'EXPLAIN', binds)
elapsed = Time.now - start
ExplainPrettyPrinter.new.pp(result, elapsed)
end
class ExplainPrettyPrinter # :nodoc:
# Pretty prints the result of a EXPLAIN in a way that resembles the output of the
# MySQL shell:
#
# +----+-------------+-------+-------+---------------+---------+---------+-------+------+-------------+
# | id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
# +----+-------------+-------+-------+---------------+---------+---------+-------+------+-------------+
# | 1 | SIMPLE | users | const | PRIMARY | PRIMARY | 4 | const | 1 | |
# | 1 | SIMPLE | posts | ALL | NULL | NULL | NULL | NULL | 1 | Using where |
# +----+-------------+-------+-------+---------------+---------+---------+-------+------+-------------+
# 2 rows in set (0.00 sec)
#
# This is an exercise in Ruby hyperrealism :).
def pp(result, elapsed)
widths = compute_column_widths(result)
separator = build_separator(widths)
pp = []
pp << separator
pp << build_cells(result.columns, widths)
pp << separator
result.rows.each do |row|
pp << build_cells(row, widths)
end
pp << separator
pp << build_footer(result.rows.length, elapsed)
pp.join("\n") + "\n"
end
private
def compute_column_widths(result)
[].tap do |widths|
result.columns.each_with_index do |column, i|
cells_in_column = [column] + result.rows.map {|r| r[i].nil? ? 'NULL' : r[i].to_s}
widths << cells_in_column.map(&:length).max
end
end
end
def build_separator(widths)
padding = 1
'+' + widths.map {|w| '-' * (w + (padding*2))}.join('+') + '+'
end
def build_cells(items, widths)
cells = []
items.each_with_index do |item, i|
item = 'NULL' if item.nil?
justifier = item.is_a?(Numeric) ? 'rjust' : 'ljust'
cells << item.to_s.send(justifier, widths[i])
end
'| ' + cells.join(' | ') + ' |'
end
def build_footer(nrows, elapsed)
rows_label = nrows == 1 ? 'row' : 'rows'
"#{nrows} #{rows_label} in set (%.2f sec)" % elapsed
end
end
# FIXME: re-enable the following once a "better" query_cache solution is in core
#
# The overrides below perform much better than the originals in AbstractAdapter
# because we're able to take advantage of mysql2's lazy-loading capabilities
#
# # Returns a record hash with the column names as keys and column values
# # as values.
# def select_one(sql, name = nil)
# result = execute(sql, name)
# result.each(as: :hash) do |r|
# return r
# end
# end
#
# # Returns a single value from a record
# def select_value(sql, name = nil)
# result = execute(sql, name)
# if first = result.first
# first.first
# end
# end
#
# # Returns an array of the values of the first column in a select:
# # select_values("SELECT id FROM companies LIMIT 3") => [1,2,3]
# def select_values(sql, name = nil)
# execute(sql, name).map { |row| row.first }
# end
# Returns an array of arrays containing the field values.
# Order is the same as that returned by +columns+.
def select_rows(sql, name = nil, binds = [])
execute(sql, name).to_a
end
# Executes the SQL statement in the context of this connection.
def execute(sql, name = nil)
if @connection
# make sure we carry over any changes to ActiveRecord::Base.default_timezone that have been
# made since we established the connection
@connection.query_options[:database_timezone] = ActiveRecord::Base.default_timezone
end
super
end
def exec_query(sql, name = 'SQL', binds = [])
result = execute(sql, name)
ActiveRecord::Result.new(result.fields, result.to_a)
end
alias exec_without_stmt exec_query
# Returns an ActiveRecord::Result instance.
def select(sql, name = nil, binds = [])
exec_query(sql, name)
end
def insert_sql(sql, name = nil, pk = nil, id_value = nil, sequence_name = nil)
super
id_value || @connection.last_id
end
alias :create :insert_sql
def exec_insert(sql, name, binds, pk = nil, sequence_name = nil)
execute to_sql(sql, binds), name
end
def exec_delete(sql, name, binds)
execute to_sql(sql, binds), name
@connection.affected_rows
end
alias :exec_update :exec_delete
def last_inserted_id(result)
@connection.last_id
end
private
def connect
@connection = Mysql2::Client.new(@config)
configure_connection
end
def configure_connection
@connection.query_options.merge!(:as => :array)
super
end
def version
@version ||= @connection.info[:version].scan(/^(\d+)\.(\d+)\.(\d+)/).flatten.map { |v| v.to_i }
end
def set_field_encoding field_name
field_name
end
end
end
end