Sep 8, 2025 · In SQL, UNION and UNION ALL are used to combine results from multiple SELECT statements. UNION returns only unique rows, whereas UNION ALL includes all rows, keeping …

Sep 8, 2008 · The UNION ALL command is equal to the UNION command, except that UNION ALL selects all values. The difference between Union and Union all is that Union all will not eliminate …

May 28, 2021 · This article compares UNION vs. UNION ALL in SQL, showing the key differences between the two using clear explanations and practical examples.

The UNION command combines the result set of two or more SELECT statements (only distinct values) The following SQL statement returns the cities (only distinct values) from both the "Customers" and …

Learn the difference between SQL UNION and UNION ALL with clear examples, when to use each, performance tips, and common pitfalls. Perfect for beginners and interview prep.

Oct 1, 2025 · Discover the key differences between SQL's UNION and UNION ALL operators, their use cases, performance implications, and best practices for efficient queries.

Jul 25, 2025 · Explore the fundamental distinctions between SQL's UNION and UNION ALL operators, including their impact on performance, duplicate handling, and data types.

SQL UNION and UNION ALL operators combine rows from multiple tables into a single result set. UNION returns only distinct rows, while UNION ALL returns all rows, including duplicates.

Jul 19, 2024 · The key difference is that UNION removes duplicate records, whereas UNION ALL includes all duplicates. This distinction not only changes the number of rows in the query result, but it …

Apr 26, 2025 · The UNION will combine two or more select statements to remove the duplicates, whereas the UNION ALL will not remove the duplicates but instead concatenate all the records, …