The following are the datatypes used in SQL: -

Character Data Types in SQL: -

CHAR( size)[BYTE | CHAR] Fixed-length character data of length size bytes. Maximum size is 2000 bytes. Default and minimum size is 1 byte. BYTE and CHAR have the same semantics as for VARCHAR2.

NCHAR( size) Fixed-length character data of length size characters. Maximum size is determined by the national character set definition, with an upper limit of 2000 bytes. Default and minimum size is 1 character.

VARCHAR2( size) [BYTE | CHAR] Variable-length character string having maximum length size bytes or characters. Maximum size is 4000 bytes, and minimum is 1 byte or 1 character. You must specify size for VARCHAR2. BYTE indicates that the column will have byte length semantics; CHAR indicates that the column will have character semantics.

NVARCHAR2( size) Variable-length character string having maximum length size characters. Maximum size is determined by the national character set definition, with an upper limit of 4000 bytes. You must specify size for NVARCHAR2.

Numeric Data Types in SQL: -

NUMBER( p,s) Number having precision p and scale s. The precision p can range from 1 to 38. The scale s can range from -84 to 127.

LONG Character data of variable length up to 2 gigabytes, or 2 31 -1 bytes.

Date, Time and Interval Data Types: -

DATE Valid date range from January 1, 4712 BC to December 31, 9999 AD. 180

TIMESTAMP ( fractional_ seconds_precision) Year, month, and day values of date, as well as hour, minute, and second values of time, where fractional_seconds_precisionis the number of digits in the fractional part of the SECOND datetime field. Accepted values of fractional_ seconds_precision are 0 to 9. The default is 6.

TIMESTAMP ( fractional_ seconds_precision) WITH TIME ZONE All values of TIMESTAMP as well as time zone displacement value, where fractional_ seconds_precisionis the number of digits in the fractional part of the SECOND datetime field. Accepted values are 0 to 9. The default is 6. 231

TIMESTAMP ( fractional_ seconds_precision) WITH LOCAL TIME ZONE All values of TIMESTAMP WITH TIME ZONE, with the following exceptions: n Data is normalized to the database time zone when it is stored in the database. n When the data is retrieved, users see the data in the session time zone.

INTERVAL YEAR ( year_precision) TO MONTH Stores a period of time in years and months, where year_precision is the number of digits in the YEAR datetime field. Accepted values are 0 to 9. The default is 2.

INTERVAL DAY (day_ precision) TO SECOND ( fractional_ seconds_precision) Stores a period of time in days, hours, minutes, and seconds, where n day_precision is the maximum number of digits in the DAY datetime field. Accepted values are 0 to 9. The default is 2. n fractional_seconds_precision is the number of digits in the fractional part of the SECOND field. Accepted values are 0 to 9. The default is 6.

Raw and Long Raw Data Types: -

RAW( size) Raw binary data of length size bytes. Maximum size is 2000 bytes. You must specify size for a RAW value.

LONG RAW Raw binary data of variable length up to 2 gigabytes.

RowID Data Types: -

ROWID Base 64 string representing the unique address of a row in its table. This datatype is primarily for values returned by the ROWID pseudocolumn.

UROWID [( size)] Base 64 string representing the logical address of a row of an index-organized table. The optional size is the size of a column of type UROWID. The maximum size and default is 4000 bytes.

Large Object Data Types (LOB's): -

CLOB A character large object containing single-byte characters. Both fixed-width and variable-width character sets are supported, both using the CHAR database character set. Maximum size is 4 gigabytes.

NCLOB A character large object containing Unicode characters. Both fixed-width and variable-width character sets are supported, both using the NCHAR database character set. Maximum size is 4 gigabytes. Stores national character set data.

BLOB A binary large object. Maximum size is 4 gigabytes.

BFILE Contains a locator to a large binary file stored outside the database. Enables byte stream I/O access to external LOBs residing on the database server. Maximum size is 4 gigabytes.