各类型对照

Rails	db2	mysql	openbase	Oracle
:binary	blob(32678)	blob	object	blob
:boolean	decimal(1)	tinyint(1)	boolean	number(10)
:date	date	date	date	date
:datetime	timestamp	datetime	datetime	date
:decimal	decimal	decimal	decimal	decimal
:float	float	float	float	number
:integer	int	int(11)	integer	number(38)
:string	varchar(255)	varchar(255)	char(4096)	varchar2(255)
:text	clob(32768)	text	text	clob
:time	time	time	time	date
:timestamp	timestamp	datetime	timestamp	date
Rails	postgresql	sqlite	sqlserver	Sybase
:binary	bytea	blob	image	image
:boolean	boolean	boolean	bit	bit
:date	date	date	datetime	datetime
:datetime	timestamp	datetime	datetime	datetime
:decimal	decimal	decimal	decimal	decimal
:float	float	float	float(8)	float(8)
:integer	integer	integer	int	int
:string	*	varchar(255)	varchar(255)	varchar(255)
:text	text	text	text	text
:time	time	datetime	datetime	time
:timestamp	timestamp	datetime	datetime	timestamp