Conceptual data type	DBMS-specific physical data type	Content	Length
Integer	int / INTEGER	32-bit integer
Short Integer	smallint / SMALLINT	16-bit integer
Long Integer	int / INTEGER	32-bit integer
Byte	tinyint / SMALLINT	256 values
Number	numeric / NUMBER	Numbers with a fixed decimal point	Fixed
Decimal	decimal / NUMBER	Numbers with a fixed decimal point	Fixed
Float	float / FLOAT	32-bit floating point numbers	Fixed
Short Float	real / FLOAT	Less than 32-bit point decimal number
Long Float	double precision / BINARY DOUBLE	64-bit floating point numbers
Money	money / NUMBER	Numbers with a fixed decimal point	Fixed
Serial	numeric / NUMBER	Automatically incremented numbers	Fixed
Boolean	bit / SMALLINT	Two opposing values (true/false; yes/no; 1/0)
Characters	char / CHAR	Character strings	Fixed
Variable Characters	varchar / VARCHAR2	Character strings	Maximum
Long Characters	varchar / CLOB	Character strings	Maximum
Long Var Characters	text / CLOB	Character strings	Maximum
Text	text / CLOB	Character strings	Maximum
Multibyte	nchar / NCHAR	Multibyte character strings	Fixed
Variable Multibyte	nvarchar / NVARCHAR2	Multibyte character strings	Maximum
Date	date / DATE	Day, month, year
Time	time / DATE	Hour, minute, and second
Date & Time	datetime / DATE	Date and time
Timestamp	timestamp / TIMESTAMP	System date and time
Binary	binary / RAW	Binary strings	Maximum
Long Binary	image / BLOB	Binary strings	Maximum
Bitmap	image / BLOB	Images in bitmap format (BMP)	Maximum
Image	image / BLOB	Images	Maximum
OLE	image / BLOB

可配合：学习