Module: ArJdbc::MySQL::Column

Included in:
ActiveRecord::ConnectionAdapters::MysqlAdapter::Column
Defined in:
lib/arjdbc/mysql/column.rb

Overview

Column behavior based on (abstract) MySQL adapter in Rails.

See Also:

Instance Method Summary collapse

Instance Method Details

#extract_default(default) ⇒ Object 



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# File 'lib/arjdbc/mysql/column.rb', line 13

def extract_default(default)
  if sql_type =~ /blob/i || type == :text
    if default.blank?
      return null ? nil : ''
    else
      raise ArgumentError, "#{type} columns cannot have a default value: #{default.inspect}"
    end
  elsif missing_default_forged_as_empty_string?(default)
    nil
  else
    super
  end
end

#extract_limit(sql_type) ⇒ Object 



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# File 'lib/arjdbc/mysql/column.rb', line 76

def extract_limit(sql_type)
  case sql_type
  when /blob|text/i
    case sql_type
    when /tiny/i
      255
    when /medium/i
      16777215
    when /long/i
      2147483647 # mysql only allows 2^31-1, not 2^32-1, somewhat inconsistently with the tiny/medium/normal cases
    else
      super # we could return 65535 here, but we leave it undecorated by default
    end
  when /^bigint/i;    8
  when /^int/i;       4
  when /^mediumint/i; 3
  when /^smallint/i;  2
  when /^tinyint/i;   1
  when /^enum\((.+)\)/i # 255
    $1.split(',').map{ |enum| enum.strip.length - 2 }.max
  when /^(bool|date|float|int|time)/i
    nil
  else
    super
  end
end

#has_default? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/arjdbc/mysql/column.rb', line 27

def has_default?
  return false if sql_type =~ /blob/i || type == :text #mysql forbids defaults on blob and text columns
  super
end

#missing_default_forged_as_empty_string?(default) ⇒ Boolean

MySQL misreports NOT NULL column default when none is given. We can't detect this for columns which may have a legitimate '' default (string) but we can for others (integer, datetime, boolean, and the rest).

Test whether the column has default '', is not null, and is not a type allowing default ''.

Returns:

  • (Boolean) 


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# File 'lib/arjdbc/mysql/column.rb', line 110

def missing_default_forged_as_empty_string?(default)
  type != :string && !null && default == ''
end

#simplified_type(field_type) ⇒ Object 



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# File 'lib/arjdbc/mysql/column.rb', line 32

def simplified_type(field_type)
  if adapter && adapter.emulate_booleans?
    return :boolean if field_type.downcase.index('tinyint(1)')
  end

  case field_type
  when /enum/i, /set/i then :string
  when /year/i then :integer
  # :tinyint : {:name=>"tinyint", :limit=>3}
  # :"tinyint unsigned" : {:name=>"tinyint unsigned", :limit=>3}
  # :bigint : {:name=>"bigint", :limit=>19}
  # :"bigint unsigned" : {:name=>"bigint unsigned", :limit=>20}
  # :integer : {:name=>"integer", :limit=>10}
  # :"integer unsigned" : {:name=>"integer unsigned", :limit=>10}
  # :int : {:name=>"int", :limit=>10}
  # :"int unsigned" : {:name=>"int unsigned", :limit=>10}
  # :mediumint : {:name=>"mediumint", :limit=>7}
  # :"mediumint unsigned" : {:name=>"mediumint unsigned", :limit=>8}
  # :smallint : {:name=>"smallint", :limit=>5}
  # :"smallint unsigned" : {:name=>"smallint unsigned", :limit=>5}
  when /int/i then :integer
  when /double/i then :float # double precision (alias)
  when 'bool' then :boolean
  when 'char' then :string
  # :mediumtext => {:name=>"mediumtext", :limit=>16777215}
  # :longtext => {:name=>"longtext", :limit=>2147483647}
  # :text => {:name=>"text"}
  # :tinytext => {:name=>"tinytext", :limit=>255}
  when /text/i then :text
  when 'long varchar' then :text
  # :"long varbinary" => {:name=>"long varbinary", :limit=>16777215}
  # :varbinary => {:name=>"varbinary", :limit=>255}
  when /binary/i then :binary
  # :mediumblob => {:name=>"mediumblob", :limit=>16777215}
  # :longblob => {:name=>"longblob", :limit=>2147483647}
  # :blob => {:name=>"blob", :limit=>65535}
  # :tinyblob => {:name=>"tinyblob", :limit=>255}
  when /blob/i then :binary
  when /^bit/i then :binary
  else
    super
  end
end