Hour 15. Combining Multiple Queries into One
During this hour, you learn how to combine SQL queries into one by using the UNION, UNION ALL, INTERSECT, and EXCEPT operators. Once again, you must check your particular implementation for any variations in the use of the UNION, UNION ALL, INTERSECT, and EXCEPT operators.
The highlights of this hour include
An overview of the operators used to combine queries
When to use the commands to combine queries
Using the GROUP BY with the compound operators
Using the ORDER BY with the compound operators
How to retrieve accurate data
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