What Are the Oracle Built-in Data Types?

by **Micheal** Sat Jan 16, 2010 9:10 pm

There are 20 Oracle built-in data types, divided into 6 groups:
Character Datatypes - CHAR, NCHAR, NVARCHAR2, VARCHAR2
Number Datatypes - NUMBER, BINARY_FLOAT, BINARY_DOUBLE
Long and Row Datatypes - LONG, LONG RAW, RAW
Datetime Datatypes - DATE, TIMESTAMP, INTERVAL YEAR TO MONTH, INTERVAL DAY TO
SECOND
Large Object Datatypes - BLOB, CLOB, NCLOB, BFILE
Row ID Datatypes - ROWID, UROWID
What Are the Differences between CHAR and NCHAR?
Both CHAR and NCHAR are fixed length character data types. But they have the following
differences:
CHAR's size is specified in bytes by default.
NCHAR's size is specified in characters by default. A character could be 1 byte to 4 bytes long
depending on the character set used.
NCHAR stores characters in Unicode.
What Are the Differences between CHAR and VARCHAR2?
The main differences between CHAR and VARCHAR2 are:
CHAR stores values in fixed lengths. Values are padded with space characters to match the
specified length.
VARCHAR2 stores values in variable lengths. Values are not padded with any characters.