Oracle Common database Fields

The database field types commonly used by Oracle are as follows:

>real

Field type	Chinese description	Restriction conditions	Other instructions
CHAR	Fixed-length strings	Max Length bytes
VARCHAR2	Variable-length strings	Maximum Length 4000 bytes	Maximum length of index can be made 749
NCHAR	Fixed-length strings based on character set	Max Length bytes
NVARCHAR2	Variable-length strings based on character set	Maximum Length 4000 bytes
DATE	Date (day-month-year)	Dd-mm-yy (HH-MI-SS)	After rigorous testing, no problem of thousand worms
LONG	Super Long string	Maximum length 2G (231-1)	Enough to store a tome
RAW	Fixed-length binary data	Max Length bytes	can store multimedia image sound, etc.
LONG RAW	Variable-length binary data	Maximum length 2G	Ditto
Blob	Binary data	Maximum length 4G
Clob	Character data	Maximum length 4G
NCLOB	Character data based on the character set	Maximum length 4G
BFILE	Binary data stored outside the database	Maximum length 4G
ROWID	Unique line number recorded in the datasheet	Bytes ********.****.**** format, * 0 or 1
Nrowid	Unique line number recorded in a Binary data table	Maximum Length 4000 bytes
Number (P,s)	Number Type	P is the integer digit, S is the decimal digit
DECIMAL (P,s)	Number Type	P is the integer digit, S is the decimal digit
INTEGER	Integer type	A small integer
FLOAT	Floating-point type	Number (38), double precision
	real type	number (63), higher precision