Oracle Forms Interview Questions and Answers

What is a window?
This object specifies the window in which the canvas object is displayed at runtime.
What is a Canvas?
This object represents a background entity on which you place interface items, such as check boxes, radio groups, and text items. There are four types of canvas objects: Content, Stacked, Horizontal Toolbar, and Vertical Toolbar.
What is Model window and Modeless window?
Model windows -- require an end user to dismiss the window before any other user interaction can continue. Modeless window --requires no end user response.
Describe Call-Form, Open-form, New-Form?

Call Form: Runs an indicated form while keeping the parent form active. Form Builder runs the called form with the same. Run form preferences as the parent form. When the called form is exited Form Builder processing resumes in the calling form at the point from which you initiated the call to CALL_FORM.

Open Form: 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.

New Form: Exits the current form and enters the indicated form. The calling form is terminated as the parent form .If the calling form had been called by a higher form, Form Builder keeps the higher call active and treats it as a call to the new form. Form Builder runs the new form with the same Run form options as the parent form. If the parent form was a called form, Form Builder runs the new form with the same options as the parent form.

What is the difference b/w Data block and Control block?
Data block is a block, which connects to the database. Control block is a block, which is not connected to the database.
Difference b/w Pre-Query and Post-Query?
Pre-Query Validate the current query criteria or provide additional query criteria programmatically, just before sending the SELECT statement to the database. Post-Query Perform an action after fetching a record, such as looking up values in other tables based on a value in the current record. Fires once for each record fetched into the block.

Trigger sequence while opening a form?

Pre-Form, 
Pre-Block, 
Pre-Record, 
Pre-Item, 
When-new-form-Instance, 
When-new-block-Instance, 
When-new-Record-instance, 
When-new-Item-instance

Types of Record-Groups?

Static Record Group: - A static record group is not associated with a query; instead, we define its structure and row values at design time, and they remain fixed at runtime. Static record groups can be created and modified only at design time.

Query Based Record Group: - A query record group is a record group that has an associated SELECT statement. The columns in a query record group derive their default names, data types, and lengths from the database columns referenced in the SELECT statement. The records in a query record group are the rows retrieved by the query associated with that record group.

Non Query Record Group: - A non-query record group is a group that does not have an associated query, but whose structure and values can be modified programmatically at runtime. Non-query record groups can be created and modified only at runtime.

How many types of canvases available in forms & which is the default canvas?

Content:- it is the base view of window which occupies the entire surface of window. It can have any no of canvases but at a time only one is visible. It is the default canvas

Stacked:-It is always displayed above the content canvas, because the content Canvas is the base view. It can have any no of stacked canvases and more than one stacked canvas can be displayed at a time. It is mainly used as headers and footers to display the tittles, dates and times etc. 

Tool bar:- A toolbar canvas often is used to create toolbars for individual windows. There are two types of tool bars Horizontal and Vertical Tool bar Canvas.
Horizontal tool bar canvases are displayed at the top of window and only one horizontal tool bar can be attached to a form module.
Vertical tool bar is used to display top to bottom on the left side of the window. 

Tab:- It is a collection of one or more tab pages. It is mainly used to display a large amount of related information a single dynamic form builder canvas object.

What is property class, visual attributes and Difference between property class & visual attribute?

Property Class:-It is a global Property sheet where we can define the properties of different objects. 

Visual Attributes:-it is used to set the visual appearance of interface objects like items, records and canvases .There are three types of visual attributes. 
Default:-It is the visual attribute by default attached to the oracle form related objects. 
Custom:-When the default VA is amended with few properties. 
User Defined: - This can be attached to the objects at design time under VA Node as well as run time programmatically. 

We can change Visual Attribute properties dynamically at runtime,but we cannot change Property class properties.
When u inherit the both Visual Attribute properties and Property class properties to an item Visual Attribute properties overrides the Property class properties

What are the triggers types in master details forms and What are the procedures that will gets created when a master details form created?
Triggers ISOLATED:- ON_CLEAR_DETAILS AND ON_POPULATE_DETAILS NON ISOLATED:- ON_CLEAR_DETAILS, ON_POPULATE_DETAILS AND ON_CHECK_DELETE_MASTER CASCADING:- ON_CLEAR_DETAILS, ON_POPULATE_DETAILS AND PRE-DELETE Procedures CHECK_PACKAGE_FAILURE CHECK_ALL_MASTER_DETAILS QUERY_MASTER_DETAILS