Commonly asked D2K Interview Questions

• Which triggers are created when Master-Detail Relationship?
• Master Delete Property
• NON-ISOLATED (by default)
1. On Check Delete Master
2. On Clear Details
3. On Populate Details
•  ISOLATED
1. On Clear Details
2. On Populate Details
• CASCADE
1. Pre-Delete
2. On Clear Details
3. On Populate Details

• What are the System variables can be set by users?
• SYSTEM.MESSAGE_LEVEL
• SYSTEM.DATE_THRESHOLD
• SYSTEM.EFFECTIVE_DATE
• SYSTEM.SUPPRESS_WORKING 

• What is Object Group?
• An Object Group is a container for a group of objects. 
• You define an object group when you want package related objects so that you can copy or reference them in another module. 

• What are referenced objects?
• Referencing allows you to create objects that inherit their functionality and appearance from other objects. 
• Referencing an object is similar to copying an object, except that the resulting reference object maintains a link to its source object. 
• A reference object automatically inherits any changes that have been made to the source object when you open or regenerate the module that contains the reference object. 

• Can you issue DDL Statement in forms?
• We can issue DDL statement in Forms by using FORMS_DDL.
• Any string expression up to 32K. A literal an expression or a variable representing the text of a block of dynamically created PL/SQL code DML statement or a DDL statement.
• Restrictions:-
• The statement you pass to FORMS_DDL may not contain bind variable references in the string, but the values of bind variables can be concatenated into the string before passing the result to FORMS_DDL.  
  

• What is secure property?
• Hides characters that the operator types into the text item.  
• This setting is typically used for  password protection. 

• What are the types of triggers and how the sequence of firing in text item?
• Triggers can be classified as Key Triggers, Mouse Triggers ,Navigational Triggers. 
• Key Triggers:
• Key Triggers are fired as a result of Key actions.
• Ex:   
• Key-next-field
• Key-up
• Key-Down, etc
• Mouse Triggers:
• Mouse Triggers are fired as a result of the mouse navigation.
• Ex:
• When-mouse-button-pressed
• when-mouse-double-clicked, etc
• Navigational Triggers:
• These Triggers are fired as a result of Navigation. 
• Ex:
• Post-Text-item
• Pre-text-item.
• We also have event triggers like when –new-form-instance and when-new-block-instance.
• We cannot call restricted procedures like go_to(‘my_block.first_item’) in the Navigational triggers but can use them in the Key-next-item.
• The Difference between Key-next and Post-Text is an very important question. 
• The key-next is fired as a result of the key action while the post text  is fired as a result of the mouse movement. 
• Key next will not fire unless there is a key event.
• The sequence of firing in a text item are as follows:
• pre-text
• when new item 
• key-next
• when validate 
• post text

• What are Property Classes?
• Property class inheritance is a powerful feature that allows you to quickly define objects that conform to your own interface and functionality standards. 
• Property classes also allow you to make global changes to applications quickly.  
• By simply changing the definition of a property class, you can change the definition of all objects that inherit properties from that class.
• Property Classes have all type of triggers.

• If you have property class attached to an Item and you have same trigger written for the item. Which will fire first?
• If item level trigger fires, property level trigger won't fire. 
• Triggers at the lowest level are always given the first preference. 
• The item level trigger fires first and then the block and then the Form level trigger.

• What are Record Groups? Can record groups create at run-time?
• A record group is an internal Oracle Forms data structure that has a column/row framework similar to a database table.  
• However, unlike database tables, record groups are separate objects that belong to the form module in which they are defined.  
• A record group can have an unlimited number of columns of type CHAR, LONG, NUMBER, or DATE provided that the total number of columns does not exceed 64K.  
• Record group column names cannot exceed 30 characters. 
• Programmatically Record Groups can be used whenever the functionality offered by a two-dimensional array of multiple data types is desirable. 

• Types of Record groups?
• Query 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.
• Static Record Group:
• A static record group is not associated with a query; rather, you define its structure and row values at design time, and they remain fixed at runtime.

• What are ALERT? 
• An Alert is a modal window that displays a message notifying operator of some application condition.

• What is mouse navigate property of button?
• When Mouse Navigate is True (the default), Oracle Forms performs standard navigation to move the focus to the item when the operator activates the item with the mouse.  
• When Mouse Navigate is set to False, Oracle Forms does not perform navigation (and the resulting validation) to move to the item when an operator activates the item with the mouse. 

• What is FORMS_MDI_WINDOW?
• Forms run inside the MDI application window. This property is useful for calling a form from another one.

• When When-Timer-Expired does not fire?
•  The When-Timer-Expired trigger can not fire during trigger, navigation, or transaction processing.

• Can object group have a block?
  • Yes , object group can have block as well as program units.