18 Questions
What is the purpose of using a subquery in the given example?
To retrieve student IDs from the scores table where the subject is 'Math' and the score is greater than 90
What SQL clause is typically used in conjunction with aggregate functions to group rows into subsets?
GROUP BY
In the given example, what is the outer query retrieving?
Average salary of employees in each department
What are the benefits of using SQL subqueries?
They allow complex queries to be broken down into simpler, more manageable parts
What is the difference between inner and outer queries in SQL?
Inner queries are executed first and outer queries are executed second
What is the purpose of using SQL subqueries in a SELECT statement?
To retrieve data based on another query result
Which clause in an SQL query can contain a subquery?
All of the above
Which SQL clause is the subquery used in the given example?
WHERE
What is the difference between an inner query and an outer query in a subquery?
The outer query is executed before the inner query
What is a benefit of using SQL subqueries?
They simplify complex queries
How can you use a subquery in an UPDATE statement?
To update a table based on the result of another query
What is a common use of SQL subqueries in the WHERE clause?
To filter data based on the result of another query
What is the primary function of an inner query in a SQL subquery?
To filter or compute values based on a condition or calculation
In which clauses can a SQL subquery be used?
In SELECT, FROM, WHERE, HAVING, INSERT, UPDATE, DELETE, and JOIN clauses
What is the purpose of the outer query in a SQL subquery?
To operate on the result set produced by the inner query
What is the benefit of using SQL subqueries?
To retrieve data based on the results of another query
What is the correct syntax for a SQL subquery?
Enclosed within parentheses
What does the inner query in the example retrieve?
Customer IDs of customers aged 30 or older
Learn about SQL subqueries, also known as nested queries or inner queries, which are queries nested within another SQL statement. Understand how subqueries are enclosed within parentheses in the WHERE or HAVING clause of another SQL query, and how they provide input for the outer query to perform further operations.
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