Each application needs a simple way to log errors and find
them. The following technique can also be used to debug Forms, Reports and PL/SQL. This version 2.0 has an important change. The username ist stored in the debugging-data and the viewname has changed a little bit.
First create the table, sequence and view to store the logging-information:
CREATE TABLE Logging (
ID NUMBER(9) NOT NULL,
SESSION_ID NUMBER(9),
INSERT_DATE DATE NOT NULL,
INSERT_USER VARCHAR2(30) NOT NULL,
TEXT VARCHAR2(2000) NOT NULL);
CREATE SEQUENCE Logging_SEQ;
CREATE OR REPLACE VIEW Logging_desc_V
(ID, SESSION_ID, INSERT_DATE, INSERT_USER, TEXT)
AS SELECT ID, SESSION_ID, INSERT_DATE, INSERT_USER, TEXT
FROM Logging
ORDER BY SESSION_ID DESC, ID DESC;
You need also a package with some functions to start the logging-process
CREATE OR REPLACE PACKAGE PK_DEBUG IS
FUNCTION Debug_allowed RETURN BOOLEAN;
FUNCTION Next_ID RETURN NUMBER;
PROCEDURE Disable;
PROCEDURE Enable;
PROCEDURE Destroy;
PROCEDURE Init (P_Debug_allowed IN BOOLEAN DEFAULT TRUE);
PROCEDURE Write (P_Text IN VARCHAR2,
P_Session_ID IN NUMBER DEFAULT NULL);
G_Debug_allowed BOOLEAN := TRUE;
G_Session_ID NUMBER;
END;
/
CREATE OR REPLACE PACKAGE BODY PK_DEBUG IS
FUNCTION Debug_allowed RETURN BOOLEAN IS
BEGIN
RETURN (G_Debug_allowed);
END;
FUNCTION Next_ID RETURN NUMBER IS
V_ID NUMBER;
BEGIN
SELECT Logging_SEQ.nextval
INTO V_ID
FROM DUAL;
RETURN (V_ID);
END;
PROCEDURE Disable IS
BEGIN
G_Debug_allowed := FALSE;
END;
PROCEDURE Enable IS
BEGIN
G_Debug_allowed := TRUE;
END;
PROCEDURE Destroy IS
BEGIN
Write ('----------------------stopp '
|| to_char (G_Session_ID) || '--');
G_Session_ID := NULL;
END;
PROCEDURE Init (
P_Debug_allowed IN BOOLEAN DEFAULT TRUE) IS
BEGIN
G_Debug_allowed := P_Debug_allowed;
G_Session_ID := Next_ID;
Write ('--start ' || to_char (G_Session_ID)
|| '----------------------');
END;
PROCEDURE Write (
P_Text IN VARCHAR2,
P_Session_ID IN NUMBER DEFAULT NULL) IS
PRAGMA AUTONOMOUS_TRANSACTION;
BEGIN
IF Debug_allowed THEN
IF G_Session_ID IS NULL THEN
Init;
END IF;
INSERT INTO Logging (ID,
Session_ID,
Insert_Date,
Insert_User,
Text)
VALUES (Next_ID,
NVL (P_Session_ID, G_Session_ID),
Sysdate,
User,
P_Text);
COMMIT;
END IF;
END;
END;
/
You start a debugging-session with
INIT and stop it with
DESTROY. Error-Messages are logged using
WRITE. For example:
pk_Debug.Init;
pk_Debug.Write ('Hello World - ' || V_Test);
pk_Debug.Destroy;
Parts of your debugging can be deactivated with
DISABLE and from this point on nothing will be written into the logging-table until you start
ENABLE.
The view
Logging_DESC_V shows you the debugging-information, group by the newest session-id.
ID Session Insert-Date Text
============================================
24 21 10.09.-12:38:48 -------stopp 21--
23 21 10.09.-12:38:48 Hello World - 42
22 21 10.09.-12:38:48 --start 21-------
Try it
Gerd
