FAQs in Oracle Forms – Part:3
November 19, 2010 2 Comments
FAQs in Oracle Forms – Part:3
What is the difference between Pre-Form and When-New-Form-Instance trigger?
Pre-Form trigger will be fired before entering into the form. It is the first trigger that fires when a form is run; fires before the form is visible. It is useful for setting access to form items, initializing global variables, and assigning unique primary key from an Oracle sequence.
When-New-Form-Instance trigger will be fired whenever form is ready to accept the data from the user.
Another main difference between the two is that you cannot navigate in a pre-from trigger (restricted) whereas you can navigate in a when-new-form-instance trigger. For example : go_block and execute-query will only work in when-new-form-instance trigger not in pre-from trigger.
What are the triggers fired while creating Master Detail form?
On-Clear Details (Form Level)
On-Populate-Details (Block Level)
On-Check-delete-Master (Block Level)
How will you get the block Name in a form?
By using SYSTEM.CURRENT_BLOCK
What is the difference between Pre-insert and On-insert trigger?
Pre-insert trigger fires during the Post and Commit Transactions process, before a row is inserted. It fires once for each record that is marked for insert. On-insert trigger fires during the Post and Commit Transactions process when a record is inserted. Specifically, it fires after the Pre-Insert trigger fires and before the Post-Insert trigger fires, when Form Builder would normally insert a record in the database. It fires once for each row that is marked for insertion into the database.
What is the difference between Pre-Query and Post-Query trigger?
Pre-Query trigger validates the current query criteria or provide additional query criteria programmatically, just before sending the SELECT statement to the database. Post-Query trigger perform an action after fetching a record, such as looking up values in other tables based on a value in the current record. It fires once for each record fetched into the block.
What is the trigger sequence while opening a form?
What is the difference between new form, open form & call form?
New_form:-Once we move into the destination automatically source will be closed.
Open_form:- It is a two way connection between source and destination. Opens the indicated form. Use OPEN_FORM to create multiple-form applications, that is, applications that open more than one form at the same time.
Call_form:- Call_form() runs an indicated form while keeping the parent form active. Without closing the destination one cannot come back to the source.
How to call a Report from a form?
By using RUN_PRODUCT Built-in.
Can we write Commit statement in forms triggers?
What is the usage of an ON-INSERT,ON-DELETE and ON-UPDATE TRIGGERS ?
These triggers are executes when inserting, deleting and updating operations are performed and can be used to change the default function of insert, delete or update respectively.
A query fetched 10 records. How many times does a PRE-QUERY Trigger and POST-QUERY Trigger will get executed ?
PRE-QUERY fires once. POST-QUERY fires 10 times.
How can you execute the user defined triggers in forms?
To execute a user-named trigger, you must call the EXECUTE_TRIGGER built-in procedure, as shown here: Execute_Trigger(‘my_user_named_trigger’);
What are Restricted Built-in Subprograms in forms?
Any built-in subprogram that initiates navigation is restricted. This includes subprograms that move the input focus from one item to another, and those that involve database transactions. Restricted built-ins are not allowed in triggers that fire in response to navigation.
For example, the GO_ITEM and NEXT_SET built-ins are both restricted procedures. GO_ITEM moves the input focus from a source item to a target item, which requires navigation. Similarly, the NEXT_SET procedure causes Oracle Forms to navigate internally to the block level, fetch a set of records, and then navigate to the first item in the first record. (Note that this navigation happens internally as a result of default processing, and may not be apparent to the form operator.) Because GO_ITEM and NEXT_SET both initiate navigation, they cannot be called from triggers that fire in response to internal navigational events; that is, triggers that fire while navigation is already occurring. Thus, a restricted procedure cannot be called from a Pre-Block trigger, because the Pre-Block trigger fires during internal navigation. In fact, restricted subprograms are not allowed from any PRE- or POST- navigational triggers. You can, however, call a restricted built-in subprogram from a When-New-Instance trigger. For example, the When-New-Item-Instance trigger fires after navigation to an item has succeeded, when the form is waiting for input.
What are System Variables in forms?
A system variable is a Oracle Forms variable that keeps track of an internal Oracle Forms state. You can reference the value of a system variable to control the way an application behaves.
List system variables available in forms 10g?
What are the triggers associated with the image item?
When-Image-activated(fires when the operator double clicks on an image Items)
When-image-pressed(fires when the operator selects or deselects the image item)
What are the built-in routines available in forms to create and manipulate a parameter list?
What are the built-ins used to trapping errors in forms?
Error_type : Returns the error message type(character)
Error_code : Returns the error number
Error_text : Returns the message text of the Oracle Forms error
Dbms_error_code : Returns the error number of the last database error that was detected.
Dbms_error_text : Returns the message number (such as ORA-01438) and message text of the database error
What is the predefined exception available in forms ?
The FORM_TRIGGER_FAILURE exception is a predefined PL/SQL exception available only in Oracle Forms.
What are the Built-ins used for sending Parameters to forms?
You can pass parameter values to a form when an application executes the call_form, New_form, Open_form or Run_product.
How do you reference a Parameter?
In pl/sql, You can reference and set the values of form parameters using bind variables syntax.
How do you reference a parameter indirectly?
To indirectly reference a parameter use the NAME_IN or COPY built-ins.
What is forms_DDL?
It issues dynamic sql statements at run time, including server side pl/sql and DDL
What is Text_io Package?
It allows you to read and write information to a file in the file system.
What is When-Database-Record trigger?
It fires when oracle forms first marks a record as an insert or an update. The trigger fires as soon as oracle forms determines through validation that the record should be processed by the next post or commit as an insert or update. It generally occurs only when the operator modifies the first item in the record, and after the operator attempts to navigate out of the item.
What is the difference between $$DATE$$ & $$DBDATE$$?
$$DBDATE$$ retrieves the current database date
$$DATE$$ retrieves the current operating system date.
What is a timer?
Timer is a “internal time clock” that you can programmatically create to perform an action each time the timer expires.
What are built-ins associated with timers?
What is the difference between post database commit and post-form commit?
Post-form commit fires once during the post and commit transactions process, after the database commit occurs. The post-form-commit trigger fires after inserts, updates and deletes have been posted to the database but before the transactions have been finalized in the issuing the command. The post-database-commit trigger fires after oracle forms issues the commit to finalized transactions.
What is the form development process?
a) open template form
b) Save as <your form>.fmb
c) Change the form module name as form name.
d) Delete the default blocks, window, and canvas
e) Create a window.
f) Assign the window property class to window
g) Create a canvas
h) Assign canvas property class to the canvas
i) Assign the window to the canvas and canvas to the window
j) Create a data block
k) Modify the form level properties. (sub class item à Text item)
l) Modify the app_cusom package. In the program unit.
m) Modify the pre-form trigger (form level)
n) Modify the module level properties
o) Save and compile the form.
p) Place the .fmx in the server directory.
q) Register in the AOL
APPLICATION à FORMà FUNCTIONà MENU
What is template?
The TEMPLATE form is the required starting point for all development of new Forms. The TEMPLATE form includes platform–independent attachments of several Libraries.
APPSCORE :- It contains package and procedures that are required of all forms to support the MENUS ,TOOLBARS.
APPSDAYPK :- It contains packages that control the oracle applications CALENDER FEATURES.
FNDSQF :- It contains packages and procedures for MESSAGE DICTONARY, FLEX FIELDS, PROFILES AND CONCURRENT PROCESSING.
CUSTOM :- It allows extension of oracle applications forms with out modification of oracle application code, you can use the custom library for customization such as zoom ( such as moving to another form and querying up specific records)
Where exactly you place your forms in APPS environment?
What are the Different PLL’s used in Forms?
What are the triggers that can be modified during Forms Customization?
What are the triggers that cannot be modified during Forms Customization?