3i Infotech Papers: Sample Questions 90 - 91 of 1245

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Question number: 90

» Database » Oracle

MCQ▾

Question

Can an Integrity Constraint be enforced on a table if some existing table data does not satisfy the constraint?

Choices

Choice (4) Response

a.

No

b.

Yes

c.

None of the above

d.

Question does not provide sufficient data or is vague

Answer

a.

Explanation

Overview of integrity constraints.

Overview of Integrity Constraints.

Overview of integrity constraints.

  • No, an integrity cannot Constraint cannot be enforced on a table if some existing table data does not satisfy the constraint.

  • Integrity constrain are used to accuracy and consistency of data in a rational database.

  • Data integrity is handled in a relational database using referential integrity.

Below the types of integrity constrains:

  • UNIQUE

    • To sure about a given column is unique

  • NOT NULL

    • To sure about that no null values are allowed

  • FOREIGN KEY

    • To sure two keys share a primary key to foreign key relationship.

The types of integrity constrains

The Types of Integrity Constrains

The types of integrity constrains

Question number: 91

» Database » Oracle

MCQ▾

Question

POST-BLOCK trigger is a….

Choices

Choice (4) Response

a.

Transactional trigger

b.

Key trigger

c.

Navigational trigger

d.

All of the above

Answer

c.

Explanation

Example of post-block trigger

Example of Post-Block Trigger

Example of post-block trigger

  • A navigational trigger

  • Fires when the focus moves off the current block.

  • Used to bring block’s current record, to a condition or to prevent the user from leaving a block based on condition.

  • Form is set to put the cursor a particular block.

  • Form builder attempts to put the cursor at a target location, if the target is outside of the current unit.

  • Does not fire when the validation unit form document property it is set to form.