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Advanced SQL
In this section, we discuss the following SQL keywords and concepts:
This section covers advanced SQL topics including set operations (UNION, INTERSECT, MINUS), subqueries, inline views, conditional logic with CASE, window functions, and techniques for complex calculations like rank, median, and running totals.
In addition, we show how Structured Query Language can be used to accomplish some of the more complex operations:
Frequently Asked Questions
- What topics are covered in advanced SQL?
- Advanced SQL covers set operations (UNION, INTERSECT, MINUS), subqueries, inline views, LIMIT/TOP for result restriction, EXISTS for conditional checks, CASE for conditional logic, window functions, AUTO INCREMENT/IDENTITY/SEQUENCE for key generation, and complex analytics like rank, median, running totals, and cumulative percentages.
- What is the difference between SQL UNION and UNION ALL?
- SQL UNION combines results from two SELECT statements and returns only distinct rows, eliminating duplicates. UNION ALL returns all rows including duplicates. UNION ALL is generally faster when you know duplicates won't exist or don't need to be removed.
- What is a SQL subquery?
- A SQL subquery is a SELECT statement nested inside another SQL statement. Subqueries can appear in the WHERE clause (to filter results), the FROM clause (as an inline view or derived table), or the SELECT clause to compute values for each row.
- What are SQL window functions?
- SQL window functions perform calculations across a set of rows related to the current row without collapsing them into a single result. Common uses include ranking rows, computing running totals, calculating moving averages, and comparing values across partitions of data.
Next: SQL UNION
This page was last updated on March 19, 2026.
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