SQLZOO, Msg 8120 Column 'xxx' is invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause. (SQL-42000)

SQL Server
Problem When using a GROUP BY clause every field in the SELECT list must be either: One of the GROUP BY terms - in this case region An aggregate function - for example SUM or COUNT An expression based on the above In the example the field `name` may not be used on the SELECT line. In a group by line each region shows up only once - however in a typical region such as Africa there are several different `name` values. WHich one should SQL pick? Solutions Remove the offending field from the SELECT line Add the field to the GROUP BY clause Aggregate the offending field	SELECT name, region, MAX(population) FROM bbc GROUP BY region
Specific to SQL Server
none

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