2.2 - LEFT JOIN
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Practice Questions
Test your understanding with targeted questions
What does a LEFT JOIN do in SQL?
💡 Hint: Think about the tables involved and which records are included.
In which scenario would you prefer using LEFT JOIN over INNER JOIN?
💡 Hint: Consider what happens when there's missing data.
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Interactive Quizzes
Quick quizzes to reinforce your learning
What does LEFT JOIN return when there are no matching records in the right table?
💡 Hint: Consider what LEFT stands for in LEFT JOIN.
True or False: LEFT JOIN omits records from the left table if there are no matches in the right table.
💡 Hint: Reflect on the definition and purpose of LEFT JOIN.
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Challenge Problems
Push your limits with advanced challenges
Suppose you have two tables: 'employees' and 'departments'. Write a LEFT JOIN query to list all employees and their departments, ensuring to include employees who might not belong to any department.
💡 Hint: Consider how employees relate to departments.
Imagine you are analyzing a customer database where some customers have not made any purchases. Formulate a LEFT JOIN query that tallies the purchases made by each customer and returns all customers regardless of whether they made a purchase or not.
💡 Hint: Remember to group your results to get counts.
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