Section 5 — Exam-Ready Mixed Practice

Write a query to show all Utah customers

SELECT * FROM Customer WHERE State = 'Utah';

Write a query to show names and cities of customers with credit scores below 700

SELECT Name, City FROM Customer WHERE CreditScore < 700;

Write a query to show customers with credit limits from 5,000 through 8,000

SELECT Name, CreditLimit FROM Customer WHERE CreditLimit BETWEEN 5000 AND 8000;

Write a query to show customers whose preferred contact method is email or text

SELECT Name, ContactPref FROM Customer WHERE ContactPref IN ('email', 'text');

Write a query to show Las Vegas customers with credit scores of at least 700

SELECT Name, City, CreditScore FROM Customer WHERE City = 'Las Vegas' AND CreditScore >= 700;

Write a query to show customers not located in Utah

SELECT Name, State FROM Customer WHERE State != 'Utah';

Write a query to show customers whose names start with “A”

SELECT Name FROM Customer WHERE Name LIKE 'A%';

Write a query to show customers with no orders placed

SELECT Name, OrdersPlaced FROM Customer WHERE OrdersPlaced IS NULL;

Write a query to show customers with a known credit limit

SELECT Name, CreditLimit FROM Customer WHERE CreditLimit IS NOT NULL;

Exam tip: WHERE filters what?

Rows, not columns.

Exam tip: Which executes first—WHERE or SELECT?

WHERE executes before SELECT.

Exam tip: When do you use IS NULL?

To test for missing/unknown data; never use = NULL.