Which of the following is NOT a valid SQL data type for storing numerical values?
FLOAT
INTEGER
DECIMAL
VARCHAR
Which normal form acts as the foundation for higher levels of normalization?
First Normal Form (1NF)
Second Normal Form (2NF)
Third Normal Form (3NF)
Boyce-Codd Normal Form (BCNF)
To change the data type of a column in an existing table, which clause should be used with the ALTER TABLE statement?
CHANGE COLUMN
MODIFY COLUMN
TRANSFORM COLUMN
UPDATE COLUMN
Which of the following is NOT a valid action for cascading actions in SQL?
ON SELECT CASCADE
ON DELETE CASCADE
ON INSERT CASCADE
ON UPDATE CASCADE
What is the primary benefit of using cascading actions in database design?
Reduced storage space
Enhanced security
Simplified data manipulation
Improved query performance
In a table with a composite key, a non-key attribute depends on only one part of the key. Which normal form is violated?
None of the above
Which of the following is NOT a common SQL data type?
ARRAY
BOOLEAN
Why is defining a clear and well-structured schema important in database design?
It simplifies data management, improves data integrity, and enhances query efficiency.
It automates the process of data entry.
It eliminates the need for using SQL queries.
It makes the database look visually appealing.
Which of the following best illustrates a table violating First Normal Form (1NF)?
An "Employee" table with EmployeeID as the primary key
A "Product" table with a ProductID, Name, and Price
A "Customer" table with columns for CustomerID, Name, and Address
An "Order" table with an OrderID and separate columns for each item ordered (e.g., Item1, Item2, Item3)
How is a one-to-many relationship represented in an ER diagram?
A single line connecting two entities
Two lines connecting two entities
A diamond connecting two entities
A line with a crow's foot symbol on one end and a single line on the other