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Learn how to use the Oracle UNION operator to combine result sets of two or more queries and remove duplicates. See how to use the UNION ALL operator to retain duplicates and sort the result set by name.
Learn how to use the UNION, UNION ALL, INTERSECT, and MINUS operators to combine multiple queries in Oracle Database. See examples, data type rules, and restrictions for each operator.
This Oracle tutorial explains how to use the Oracle UNION ALL operator with syntax and examples. The Oracle UNION ALL operator is used to combine the result sets of 2 or more SELECT statements (does not remove duplicate rows).
8 Σεπ 2008 · The difference between Union and Union all is that Union all will not eliminate duplicate rows, instead it just pulls all rows from all tables fitting your query specifics and combines them into a table.
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.
select distinct * from ( select colour, shape from my_brick_collection union all select colour, shape from your_brick_collection ); The distinct operator adds an extra sorting step to your SQL. So in most cases you'll want to use union all.
The UNION ALL command combines the result set of two or more SELECT statements (allows duplicate values). The following SQL statement returns the cities (duplicate values also) from both the "Customers" and the "Suppliers" table:
