DUMP

Syntax

Description of the illustration dump.gif

Purpose

DUMP returns a VARCHAR2 value containing the datatype code, length in bytes, and internal representation of expr. The returned result is always in the database character set. For the datatype corresponding to each code, see Table 2-2, "Storage of Scale and Precision".

The argument return_fmt specifies the format of the return value and can have any of the following values:

• 8 returns result in octal notation.

• 10 returns result in decimal notation.

• 16 returns result in hexadecimal notation.

• 17 returns result as single characters.

By default, the return value contains no character set information. To retrieve the character set name of expr, add 1000 to any of the preceding format values. For example, a return_fmt of 1008 returns the result in octal and provides the character set name of expr.

The arguments start_position and length combine to determine which portion of the internal representation to return. The default is to return the entire internal representation in decimal notation.

If expr is null, then this function returns NULL.

This function does not support CLOB data directly. However, CLOBs can be passed in as arguments through implicit data conversion.

Examples

The following examples show how to extract dump information from a string expression and a column:

SELECT DUMP('abc', 1016)
   FROM DUAL;

DUMP('ABC',1016)                          
------------------------------------------ 
Typ=96 Len=3 CharacterSet=WE8DEC: 61,62,63 

SELECT DUMP(last_name, 8, 3, 2) "OCTAL"
   FROM employees
   WHERE last_name = 'Hunold';



OCTAL
-------------------------------------------------------------------
Typ=1 Len=6: 156,157

SELECT DUMP(last_name, 10, 3, 2) "ASCII"
   FROM employees
   WHERE last_name = 'Hunold';

ASCII
--------------------------------------------------------------------
Typ=1 Len=6: 110,111