MD5_CHECKSUM Function

This function is used for lost update detection. Lost update detection ensures data integrity in applications where data can be accessed concurrently.

This function produces hidden form field(s) with a name attribute equal to 'fcs' and includes 50 inputs. APEX_ITEM.MD5_CHECKSUM also produces an MD5 checksum using the Oracle database DBMS_OBFUSCATION_TOOLKIT:

UTL_RAW.CAST_TO_RAW(DBMS_OBFUSCATION_TOOLKIT.MD5())

An MD5 checksum provides data integrity through hashing and sequencing to ensure that data is not altered or stolen as it is transmitted over a network.

Syntax

APEX_ITEM.MD5_CHECKSUM(
    p_value01   IN    VARCHAR2 DEFAULT NULL,
    p_value02   IN    VARCHAR2 DEFAULT NULL,
    p_value03   IN    VARCHAR2 DEFAULT NULL,
    ...
    p_value50   IN    VARCHAR2 DEFAULT NULL,
    p_col_sep   IN    VARCHAR2 DEFAULT '|',
    p_item_id   IN    VARCHAR2 DEFAULT NULL)
    RETURN VARCHAR2;

Parameters

Table: MD5_CHECKSUM Parameters describes the parameters available in the MD5_CHECKSUM function.

MD5_CHECKSUM Parameters

Parameter Description

Parameter	Description
`p_value01` ... `p_value50`	Fifty available inputs. If no parameters are supplied, the default to NULL
`p_col_sep`	String used to separate `p_value` inputs. Defaults to the pipe symbol (\|)
`p_item_id`	ID of the HTML form item

p_value01

...

p_value50

Fifty available inputs. If no parameters are supplied, the default to NULL

p_col_sep

String used to separate p_value inputs. Defaults to the pipe symbol (|)

p_item_id

ID of the HTML form item

Example

This function generates hidden form elements with the name 'fcs'. The values can subsequently be accessed via the APEX_APPLICATION.G_FCS array.

SELECT APEX_ITEM.MD5_CHECKSUM(ename,job,sal) md5_cks,
       ename, job, sal
FROM emp