Clarification regarding "Raise Application Error" and "seq_collision exception"

[muzu1232004]

What does the RAISE_APPLICATION_ERROR mean ? When this error is raised whether the database errors are occurred ? Please can any one explain clearly what this error means ?

Also What does the seq_collision exception means and when it will be raised under what conditions ? What is the general correction to be done when this type of error occurs ?

[amitpatel66]

What does the RAISE_APPLICATION_ERROR mean ? When this error is raised whether the database errors are occurred ? Please can any one explain clearly what this error means ?

Also What does the seq_collision exception means and when it will be raised under what conditions ? What is the general correction to be done when this type of error occurs ?

RAISE_APPLICATION_ERROR is used to create a user defined error messages.

The user defined messages are associated with the user defined number (SQLCODE) using RAISE_APPLICATION_ERROR.

Eg:
DECLARE
a NUMBER := 0;
b NUMBER := 10;
BEGIN
IF(a = 0) THEN
RAISE_APPLICATION_ERROR(-20000,' Cannot Divide by Zero');
ELSE
b: = b/a;
END IF;
END;

The number passed in the RAISE_APPLICATION_ERROR should be negative and between -20000 and -20999

[AdusumalliGopikumar]

Raise_application_Error is used to defined a user defined exceptions to the stored sub programmes

raise_application_error(-20001,'user defined exception',TRUE/FLASE);

if 3rd arg is TRUE it stores the user defined exceptions in Stack

if it is FALSE then it will clear all from stack

it's range starts from -20001 to -99999