Avg Aggregate Function in SQL Server

Avg Aggregate Function:-
Returns the average of the values in a group. Null values are ignored. May be followed by the OVER clause.

Remarks :

• If the data type of expression is an alias data type, the return type is also of the alias data type. However, if the base data type of the alias data type is promoted, for example from tinyint to int, the return value is of the promoted data type and not the alias data type.
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• AVG () computes the average of a set of values by dividing the sum of those values by the count of nonnull values. If the sum exceeds the maximum value for the data type of the return value an error will be returned.