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Reserved Words You Can’t Use

ADDITIONAL_LOAD_PATHS
ARGF
ARGV
ActionController
ActionView
ActiveRecord
ArgumentError
Array
BasicSocket
Benchmark
Bignum
Binding
CGI
CGIMethods
CROSS_COMPILING
Class
ClassInheritableAttributes
Comparable
ConditionVariable
Config
Configuration
Continuation
DRb
DRbIdConv
DRbObject
DRbUndumped
Data
Date
DateTime
Delegater
Delegator
Digest
Dir
ENV
EOFError
ERB
Enumerable
Errno
Exception
FALSE
FalseClass
Fcntl
File
FileList
FileTask
FileTest
FileUtils
Fixnum
Float
FloatDomainError
GC
Gem
GetoptLong
Hash
IO
IOError
IPSocket
IPsocket
IndexError
Inflector
Integer
Interrupt
Kernel
LN_SUPPORTED
LoadError
LocalJumpError
Logger
Marshal
MatchData
MatchingData
Math
Method
Module
Mutex
Mysql
MysqlError
MysqlField
MysqlRes
NIL
NameError
NilClass
NoMemoryError
NoMethodError
NoWrite
NotImplementedError
Numeric
OPT_TABLE
Object
ObjectSpace
Observable
PGError
PGconn
PGlarge
PGresult
PLATFORM
PStore
ParseDate
Precision
Proc
Process
Queue
RAKEVERSION
RELEASE_DATE
RUBY
RUBY_PLATFORM
RUBY_RELEASE_DATE
RUBY_VERSION
Rake
RakeApp
RakeFileUtils
Range
RangeError
Rational
Regexp
RegexpError
Request
Responder
RuntimeError
STDERR
STDIN
STDOUT
ScanError
ScriptError
SecurityError
Signal
SignalException
SimpleDelegater
SimpleDelegator
Singleton
SizedQueue
Socket
SocketError
StandardError
String
StringScanner
Struct
Symbol
SyntaxError
SystemCallError
SystemExit
SystemStackError
TCPServer
TCPSocket
TCPserver
TCPsocket
TOPLEVEL_BINDING
TRUE
Task
Text
Thread
ThreadError
ThreadGroup
Time
Transaction
TrueClass
TypeError
UDPSocket
UDPsocket
UNIXServer
UNIXSocket
UNIXserver
UNIXsocket
UnboundMethod
Url
VERSION
Verbose
YAML
ZeroDivisionError

Other Names Reported to Have Caused Trouble

action – overwritten by Rails when used with form parameters (i.e. an ActionsController expecting action[field_name] won't work)
attributes – if you have a has_many called attributes, you can’t access to your object attributes anymore; only the associated objects
application
@base_path – setting this variable name in a controller method seems to break the ablity to render a partial in the view. The view will render with no content and no errors will be generated .
configuration - conflicts with rails runtime object attr array containing ['dev','test','production']
connection – there seems to be a connection class already
dispatcher
display
field_changed
format
image - Due to that there is an image_path helper, using images as a restful route will cause issues.
key
load – When making an Ajax call to an action named load, the action’s code will be skipped (or otherwise rendered useless). This is made apparent by: a) @variables are not available in the view, b) calling render :layout ⇒ false still yields the layout.
new, override to news if you want a news table
notify – not a valid name for a column or a model method
open – not a valid column name
quote ‘quote’ cannot be used as a column name
request
records – a table named records seemed to cause duplicate entries to be found by find
responses – scaffold borks with “undefined method ‘body=’ ”
scope
send
session (session_controller or SessionController will not work)
system – a table column named system causes problems when trying to generate scaffold
target – conflicts with Rails' AssociationProxy when used as a model or attribute; see this post for more information
template – a table named templates causes an error when you try to invoke the create method of the default controller
test (however those work with ruby test/unit/axis_test.rb and rake test_units)
timeout – an ActiveRecord attribute named timeout will clash with the global function “timeout” defined in Ruby’s timeout.rb
to_s—naming a model instance method to_s resulted in ‘File not found’ for any view an object of this class (should have) appeared in (no matter which method called) and WebRick had to be restarted. I couldn’t drag the very cause into light, but in the traces ‘to_s’ gave me a hint. After renaming everything worked well again.
type—or any of the other MagicFieldNames
URI

singular names finishing in “s”: Axis → Axes, Access → Accesses, will break the pluralization in rake: Axi, Acces Names You Can’t Use from SQL

The list of reserved words is dependent on the database you use, for portability reasons it would be wise to not chose a field name listed in any of these tables:

SQL-92, SQL-99 and SQL-2003 Reserved Words
PostgreSQL Key Words
MySQL Reserved Words
SQL Server, ODBC, and SQL Server Future Keywords

If you aren’t sure, you can check the word against the SQL Reserved Words Checker

Also note that numerous field names have special properties. See the full list of MagicFieldNames. Typical Errors

The errors that occur when you use a reserved word tend to be very confusing. Things that you think are happening in your code, are actually happening somewhere in the framework. Sometimes you can look at the stack trace and see that its not going through your class, but through some framework class. If you have an error that makes no sense at all, I would check to make sure you don’t have a name that conflicts with the above list.

In one instance I got a mysql error when I tried to save a model that belongs_to :quote. The belongs_to made a method that overrode the quote method in activerecord::base, which caused Quote objects to be returned where activerecord was expecting a quoted string! Requests

rails reverse words you can't use them in as your column or tablename

Reserved Words You Can’t Use

Other Names Reported to Have Caused Trouble

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