class Mysql2::Error - mysql2-0.3.21 Documentation

# class Mysql2::Error

### Constants

ENCODE_OPTS
REPLACEMENT_CHAR

### Attributes

errno[RW]
error_number[RW]
server_version[W]
sql_state[R]

### Public Class Methods

new(msg, server_version=nil) click to toggle source
Calls superclass method

    # File lib/mysql2/error.rb, line 15
    def initialize(msg, server_version=nil)
      self.server_version = server_version

      super(clean_message(msg))
    end

### Public Instance Methods

sql_state=(state) click to toggle source

    # File lib/mysql2/error.rb, line 21
    def sql_state=(state)
      @sql_state = ''.respond_to?(:encode) ? state.encode(ENCODE_OPTS) : state
    end

### Private Instance Methods

clean_message(message) click to toggle source

In MySQL 5.5+ error messages are always constructed server-side as UTF-8 then returned in the encoding set by the `character_set_results` system variable.

See dev.mysql.com/doc/refman/5.5/en/charset-errors.html for more context.

Before MySQL 5.5 error message template strings are in whatever encoding is associated with the error message language. See dev.mysql.com/doc/refman/5.1/en/error-message-language.html for more information.

The issue is that the user-data inserted in the message could potentially be in any encoding MySQL supports and is insert into the latin1, euckr or koi8r string raw. Meaning there's a high probability the string will be corrupt encoding-wise.

See dev.mysql.com/doc/refman/5.1/en/charset-errors.html for more information.

So in an attempt to make sure the error message string is always in a valid encoding, we'll assume UTF-8 and clean the string of anything that's not a valid UTF-8 character.

Except for if we're on 1.8, where we'll do nothing ;)

Returns a valid UTF-8 string in Ruby 1.9+, the original string on Ruby 1.8

    # File lib/mysql2/error.rb, line 54
    def clean_message(message)
      return message if !message.respond_to?(:encoding)

      if @server_version && @server_version > 50500
        message.encode(ENCODE_OPTS)
      else
        if message.respond_to? :scrub
          message.scrub(REPLACEMENT_CHAR).encode(ENCODE_OPTS)
        else
          # This is ugly as hell but Ruby 1.9 doesn't provide a way to clean a string
          # and retain it's valid UTF-8 characters, that I know of.

          new_message = "".force_encoding(Encoding::UTF_8)
          message.chars.each do |char|
            if char.valid_encoding?
              new_message << char
            else
              new_message << REPLACEMENT_CHAR
            end
          end
          new_message.encode(ENCODE_OPTS)
        end
      end
    end