Computer Science - IT MCQs
Topic Notes: Computer Science - IT
<p>MCQs and preparation resources for competitive exams, covering important concepts, past papers, and detailed explanations.</p>
Plato
- Biography: Ancient Greek philosopher (427–347 BCE), student of Socrates and teacher of Aristotle, founder of the Academy in Athens.
- Important Ideas:
- Theory of Forms
- Philosopher-King
- Ideal State
191
In a One-to-Many relationship between a "Customers" table and an "Orders" table, the primary key of the Customers table would be the _________ in the Orders table.
Answer:
Foreign Key
The `CustomerID` field, which is the primary key in the Customers table, is added to the Orders table to link each order to a customer. In the Orders table, `CustomerID` is the foreign key.
192
What does "Referential Integrity" ensure?
Answer:
That the relationships between tables remain consistent and valid
Enforcing referential integrity prevents "orphan" records. For example, it would prevent you from creating an order for a `CustomerID` that does not exist in the Customers table.
193
The most common type of relationship between two tables in a relational database is:
Answer:
One-to-Many
This relationship is very common. For example, one customer (the "one" side) can have many orders (the "many" side).
194
What is a "Foreign Key"?
Answer:
A primary key from one table that is placed into a second table to form a relationship
A foreign key is the "link" between two tables. For example, the `CustomerID` (primary key in the Customers table) would be placed in the Orders table as a foreign key to link each order to a specific customer.
195
What is a "Primary Key" in a database table?
Answer:
A field, or combination of fields, that uniquely identifies each record in the table
The primary key is crucial for ensuring that you can uniquely identify every single row. It cannot contain duplicate values and cannot be null (empty).
196
A "Module" in Access is an object that contains:
Answer:
Custom programming code written in Visual Basic for Applications (VBA)
Modules are for advanced automation. When the capabilities of macros are not sufficient, developers write VBA code in modules to create complex custom functions and procedures. ### Relationships and Keys (Primary, Foreign)
197
When you first open an Access table, you are in _________ View.
Answer:
Datasheet
The default view for a table is Datasheet View, as this is the view used for viewing and interacting with the data itself.
198
In a report's Design View, controls in the "Report Header" section will appear:
Answer:
Only at the very beginning of the entire report
The Report Header is for titles, logos, or information that should only be printed once at the start of the report. The Page Header is for information that repeats on every page.
199
The "AutoNumber" data type is useful for:
Answer:
Automatically generating a unique number for each new record, often used as a primary key
AutoNumber ensures that every record has a unique identifier without requiring the user to manually enter one. Access handles the incrementing automatically.
200
To combine data from two separate tables that have a common field, you would use a:
Answer:
Query
Queries are the tool used to join related tables. By linking the tables on their common field (e.g., CustomerID), you can pull fields from both tables into a single result set.