The UNION ALL operator is used to combine the result-set of two or more SELECT statements. The UNION ALL operator includes all rows from each statement, including any duplicates.

Feb 10, 2026 · The SQL UNION ALL operator combines the result sets of two or more SELECT statements into a single output. Unlike UNION, it does not remove duplicate rows, making it faster …

This SQL tutorial explains how to use the SQL UNION ALL operator with syntax and examples. The SQL UNION ALL operator is used to combine the result sets of 2 or more SELECT statements (does …

Nov 18, 2025 · The following examples use UNION to combine the results of the same table to demonstrate the effects of ALL and parentheses when using UNION. The first example uses UNION …

Learn the key differences between UNION and UNION ALL in SQL. Visual examples showing when duplicates matter, performance tips, and a decision flowchart.

What Is the SQL UNION ALL Operator? The UNION ALL operator combines the result sets of two or more SELECT statements into a single result set, preserving all rows, including duplicates.

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.

The SQL Union operator combines multiple SELECT statements and returns the distinct rows. The Union All operator also combines multiple SELECT statements but returns all rows, including …

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.