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.

Nov 17, 2025 · UNION ALL Operator is used to combine the results of two or more SELECTstatements into a single result set. Unlike the UNION operator, which eliminates …

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.

Nov 29, 2025 · UNION ALL takes all rows from multiple queries and combines them without removing duplicates. Use it when you need complete data with every row preserved, when you …

Jul 21, 2025 · UNION and UNION ALL are essential SQL tools for combining query results. Whether you're aggregating records from partitions or unifying multi-system data, knowing …

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.

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 …

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 …

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 …

Jul 25, 2025 · When working with relational databases and combining results from multiple queries, SQL developers frequently encounter the UNION and UNION ALL operators. While …