Database-Oracle [3i Infotech Placement]: Sample Questions 1 - 2 of 132
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Question 1
Question MCQ▾
Can an Integrity Constraint be enforced on a table if some existing table data does not satisfy the constraint?
Choices
Choice (4) | |
---|---|
a. | Yes |
b. | No |
c. | None of the above |
d. | All of the above |
Answer
b.Explanation
- 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.
Question 2
Question MCQ▾
POST-BLOCK trigger is a … .
Choices
Choice (4) | |
---|---|
a. | Navigational trigger |
b. | Key trigger |
c. | Transactional trigger |
d. | None of the above |
Answer
a.Explanation
- 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.