pub trait ValidGrouping<GroupByClause> {
type IsAggregate;
}Expand description
Is this expression valid for a given group by clause?
Implementations of this trait must ensure that aggregate expressions are not mixed with non-aggregate expressions.
For generic types, you can determine if your sub-expressions can appear
together using the MixedAggregates trait.
GroupByClause will be a tuple containing the set of expressions appearing
in the GROUP BY portion of the query. If there is no GROUP BY, it will
be ().
This trait can be derived
Required Associated Types§
Sourcetype IsAggregate
type IsAggregate
Is this expression aggregate?
This type should always be one of the structs in the is_aggregate
module. See the documentation of those structs for more details.