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Summary: in this tutorial, you will learn how to use the Oracle UNION operator to combine result sets returned by two or more queries. The UNION operator is a set operator that combines result sets of two or more SELECT statements into a single result set.
The following statement combines the results of two queries with the UNION operator, which eliminates duplicate selected rows. This statement shows that you must match data type (using the TO_CHAR function) when columns do not exist in one or the other table:
The set operators union, intersect, and minus allow you to combine many tables into one. This tutorial will use these two tables for the queries: select * from my_brick_collection; select * from your_brick_collection;
The UNION operator is used to combine the result set of two or more SELECT statements into a single result set and then eliminates any duplicate rows from the final result set. That means the UNION Operator selects only the distinct values.
This Oracle tutorial explains how to use the Oracle UNION operator with syntax and examples. The Oracle UNION operator is used to combine the result sets of 2 or more Oracle SELECT statements. It removes duplicate rows between the various SELECT statements.
In this tutorial, we will be learning about the UNION and UNION ALL set operator in Oracle. The set operators work on the same principle as set operators in mathematics. Before we begin understanding the set operators in Oracle, lets revisit the concept of set operators in Maths through this example: Here, A and B are two sets containing numbers.
You can combine multiple queries using the set operators UNION, UNION ALL, INTERSECT, and MINUS. All set operators have equal precedence. If a SQL statement contains multiple set operators, Oracle evaluates them from the left to right if no parentheses explicitly specify another order.
