Databases Reference
In-Depth Information
Column name
Data type
Remark
APEX_USER
VARCHAR2(255)
Username of the user authenticated to
the application
MESSAGE_LEVEL
NUMBER
Can be level 1:7 (importance)
WORKSPACE_ID
NUMBER
Application Express workspace
identifier
Instrumentation of the APEX code
Code instrumentation makes it much easier to track down bugs and isolate
unexpected behavior more quickly. Code instrumentation is used to diagnose errors
and to write trace information. Besides instrumenting the database code (see
Chapter
2
,
Leveraging the Database
), instrumenting APEX code can also be very beneicial.
You can reference the DEBUG lag using the following syntax:
Substitution string
&DEBUG.
V('DEBUG')
PL/SQL
:DEBUG
Bind variable
When a page is run in the
DEBUG
mode, the debug item is automatically set to
YES
;
otherwise, it is set to
NO
. This can be useful to show region content depending on the
debug mode variable.
The following example shows a region depending on the value of the
DEBUG
variable:
Create a condition of the type PL/SQL expression.
The value expression
1
has the following value:
v('DEBUG') = 'YES'
That means when the
DEBUG
variable is equal to
'YES'
, the region is shown; when
the
DEBUG
variable is
'NO'
, the region is not shown. This way you can limit your
debug code to only execute when running in the debug mode. So you only call the
code when you need the code. When running the application in production, the
debug mode is turned off and the debug code is ignored by the APEX engine.
