W3. SQL And

Question 1

Q: What does the SQL AND operator do?

Answer 1

A: It filters records based on multiple conditions, returning records only if all conditions are true.

Question 2

Q: Write a SQL query to select all customers from Spain with names that start with “G.”

Answer 2

SELECT * FROM Customers 
WHERE Country = 'Spain' AND CustomerName LIKE 'G%';

Question 3

Q: What is the syntax for using multiple AND conditions in SQL?

Answer 3

SELECT column1, column2, …
FROM table_name
WHERE condition1 AND condition2 AND condition3 …;

Question 4

Q: How does the AND operator differ from the OR operator?

Answer 4

A: AND requires all conditions to be true, while OR requires only one condition to be true.

Question 5

Q: Write a query to select all customers from Germany, in Berlin, with a PostalCode higher than 12000.

Answer 5

SELECT * FROM Customers 
WHERE Country = 'Germany' AND City = 'Berlin' AND PostalCode > 12000;

Question 6

Q: Can you combine AND and OR operators in the same SQL query?

Answer 6

A: Yes, they can be combined, often with parentheses to ensure the correct order of conditions.

Question 7

Q: Why are parentheses important when using AND and OR together?

Answer 7

A: They clarify grouping, ensuring that conditions are evaluated in the intended order.

Question 8

Q: Write a query to select all Spanish customers with names starting with “G” or “R.”

Answer 8

SELECT * FROM Customers 
WHERE Country = 'Spain' AND (CustomerName LIKE 'G%' OR CustomerName LIKE 'R%');

Question 9

Q: What happens if you omit parentheses when combining AND and OR?

Answer 9

A: SQL may misinterpret the intended condition grouping, potentially returning incorrect results.

Question 10

Q: Write a query that returns customers who are either from Spain and start with “G” or start with “R” regardless of their country.

Answer 10

SELECT * FROM Customers 
WHERE Country = 'Spain' AND CustomerName LIKE 'G%' OR CustomerName LIKE 'R%';