Why database testing ensures data integrity in Testing Fundamentals - Challenge Your Understanding

Challenge - 5 Problems

🧠 Conceptual

intermediate

What is the main purpose of database testing in ensuring data integrity?

Choose the best explanation for why database testing is important for data integrity.

A It checks that data is stored correctly and remains accurate after operations.

B It ensures that the database server hardware is functioning properly.

C It verifies the user interface design of database management tools.

D It only tests the speed of database queries without checking data correctness.

💡 Hint

Think about what data integrity means in terms of data correctness and accuracy.

Database testing focuses on verifying that data is stored, retrieved, and updated correctly, which keeps data accurate and consistent.

🧠 Conceptual

intermediate

Which database testing activity helps prevent data corruption?

Select the database testing activity that directly helps maintain data integrity by preventing corruption.

A Checking the color scheme of the database admin interface.

B Measuring database query execution time.

C Testing data constraints like primary keys and foreign keys.

D Verifying network connectivity to the database server.

💡 Hint

Data constraints control how data relates and what values are allowed.

Testing constraints ensures that invalid or duplicate data cannot enter the database, preventing corruption.

❓ Predict Output

advanced

What is the output of this SQL query after inserting duplicate primary key?

Given a table with a primary key, what happens when you try to insert a duplicate key?

Testing Fundamentals

CREATE TABLE users (id INT PRIMARY KEY, name VARCHAR(50));
INSERT INTO users VALUES (1, 'Alice');
INSERT INTO users VALUES (1, 'Bob');

A Error: duplicate key value violates unique constraint

B Both rows inserted successfully

C Only the first row inserted, second ignored silently

D Table structure is dropped automatically

💡 Hint

Primary keys must be unique for each row.

Inserting a duplicate primary key violates the uniqueness rule, causing an error and preventing data corruption.

❓ assertion

advanced

Which assertion best verifies data integrity after a database update?

Choose the assertion that confirms data was updated correctly without corruption.

Testing Fundamentals

UPDATE accounts SET balance = balance - 100 WHERE account_id = 123;

A Assert that the balance column is of type VARCHAR

B Assert that the number of rows in accounts table is zero

C Assert that the database server is running

D Assert that SELECT balance FROM accounts WHERE account_id = 123 returns original balance minus 100

💡 Hint

Check if the data changed as expected after the update.

Verifying the updated balance matches the expected value confirms data integrity after the operation.

🔧 Debug

expert

Why does this test fail to ensure data integrity?

Identify the reason this database test does not properly verify data integrity.

Testing Fundamentals

def test_insert_user(db):
    db.execute("INSERT INTO users (id, name) VALUES (1, 'Alice')")
    result = db.query("SELECT * FROM users WHERE id = 1")
    assert result == [(1, 'Alice')]

A The INSERT statement syntax is incorrect.

B The assertion compares a tuple with a string, causing a mismatch.

C The SELECT query is missing a WHERE clause.

D The test does not connect to the database.

💡 Hint

Check the data types and structure returned by the query versus the assertion.

The query returns a tuple with id and name, but the assertion expects a list with only the name string, causing failure.