SQL Flashcard

Front

Ananya is analyzing the sales data for her online store. She wants to find out which products had sales greater than the average sales after grouping them by category. Which SQL clause should she use to filter results after aggregation?

Back

HAVING

Front

What is the default sorting order of the ORDER BY clause in SQL?

Back

Ascending

Front

Which SQL function is used to remove duplicate rows in a query result?

Back

DISTINCT

Front

What is the primary purpose of an index in a database?

Back

Speed up queries

Front

Which type of join returns only the matching rows from both tables?

Back

INNER JOIN

Front

Which normal form ensures that there are no partial dependencies?

Back

2NF

Front

Which SQL keyword is used to retrieve the top 5 records from a table?

Back

Any of the above

Front

Which is the best strategy to delete duplicate rows while keeping one instance? Options: DELETE FROM table WHERE id IN (SELECT id FROM table), DELETE FROM table WHERE rownum > 1, DELETE FROM table WHERE id NOT IN (SELECT MIN(id) FROM table GROUP BY column_name), DELETE * FROM table

Back

DELETE FROM table WHERE id NOT IN (SELECT MIN(id) FROM table GROUP BY column_name)

Front

Which SQL clause is used to combine rows from multiple tables based on a condition?

Back

JOIN

Front

In SQL, which of the following operations is the fastest for retrieving a specific record?
Options:
Table scan,
Indexed lookup,
Sorting,
Aggregation

Back

Indexed lookup