[Communication] EF rollup function usage precautions Max()/Min(), etc

1. The maximum value of the string type

1. The maximum value of the string type is the same as the last dictionary sort of the database, if there is a return of null

2. The maximum value of the number type

1. The maximum value of the number type is the same as the last one sorted by the database field, if no data throws an exception.

Number type, the data obtained from the condition does not throw exceptions
Additional information: The cast to the value type "System.Decimal" failed because the materialized value was null.
The generic parameter or query of the result type must be of a type that can be null.

Solution 1 (recommended):

The generated SQL is as follows:

Solution 2:

Solution 3: