Computer Science/IT MCQs
Topic Notes: Computer Science/IT
MCQs and preparation resources for competitive exams, covering important concepts, past papers, and detailed explanations.
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
6241
What is the main difference between "importing" data from Excel and "linking" to an Excel file?
Answer:
Importing creates a copy of the data in Access; linking creates a live connection to the original Excel file.
If you link to an Excel file, any changes made to the data in the original spreadsheet will be visible in Access, and vice-versa (if the link is editable). An imported table is a static snapshot and has no connection to the original file.
6242
"Exporting" data from Access means:
Answer:
Saving data from an Access object (like a table or query) into an external file format
Exporting is the process of sending data out of Access to be used in another application, such as creating an Excel spreadsheet from a query's results.
6243
"Importing" data into Access means:
Answer:
Creating a new table in Access and populating it with a copy of data from an external source
Importing creates a new, independent copy of the external data inside your Access database. Changes made to the original source file will not be reflected in the imported Access table.
6244
Before running an action query, it's a good practice to:
Answer:
Back up the entire database
Action queries make permanent changes to your data and often cannot be undone. Previewing the changes with a select query is also a good idea, but making a backup of the database file is the safest precaution against accidental data loss. ### Importing and Exporting Data
6245
To perform a calculation in a query, you create a new field and type an _________ into it.
Answer:
Expression
An expression is a combination of field names, operators (like +, -, *, /), and functions that results in a single value. For example, `NewField: [UnitPrice] * 1.1` is an expression.
6246
The SQL statement `SELECT * FROM Customers;` will:
Answer:
Select all fields from the Customers table
The asterisk (`*`) is a shortcut in SQL that means "all columns" or "all fields".
6247
The `Is Null` criterion is used to find records where:
Answer:
A field has an empty or blank value
`Is Null` is the correct syntax for finding records where no data has been entered into a particular field.
6248
An "Inner Join" (the default join type in Access) will return:
Answer:
Only the records where the joined fields from both tables are equal
An inner join only includes rows that have a match in the other table. If a customer has placed no orders, that customer will not appear in a query that uses an inner join between Customers and Orders.
6249
A "Join" in a query is used to:
Answer:
Combine records from two or more related tables based on a common field
A join is the mechanism that allows queries to pull related data from multiple tables. The line that appears between tables in the design view represents the join.
6250
What is the result of using the `OR` row in the query design grid?
Answer:
It allows a record to be included if it meets the criteria on the "Criteria" row OR the criteria on the "Or" row.
Putting criteria on separate rows broadens the search. For example, putting "London" in the City field's Criteria row and "Paris" in the Or row will find customers from either London or Paris.