Friday, May 11, 2018 Class Reflection In this class we covered some useful SQL queries. GROUP BY The first statement we covered was the GROUP BY statement. This statement groups results under the specified columns like this: SELECT Country, Region, SUM(Sales) As TotalSales FROM Sales GROUP BY Country, Region; This statement will group the sum of sales per region, and each region will be grouped under the country it belongs to. There is also GROUP BY ROLLUP and GROUP BY CUBE statements which group them differently. You can also group GROUP BY statements together with a GROUPING SET statement. It is a simplified version of a UNION that concatenates GROUP BY statements into one table of results. VIEW A view is a useful for giving certain users a certain view of the database. In a view you can set the tables and columns that are able to be seen in that view, then if someone uses that view they can only access the data available in the view. It...
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