public ValueTask <IQueryable> Visit(ExecuteGroupByStage executeGroupByStage)
{
Debug.Assert(queryable != null);
var groupByExecutor = _groupByExecutorFactory.GetGroupByExecutor(executeGroupByStage);
return(groupByExecutor.Execute(queryable, executeGroupByStage));
}
public IGroupByExecutor GetGroupByExecutor(ExecuteGroupByStage groupByStage)
{
var t = typeof(DefaultGroupByExecutor <,>).MakeGenericType(groupByStage.ValueType, groupByStage.KeyType);
var executor = (IGroupByExecutor)Activator.CreateInstance(t);
return(executor);
}
protected Expression <Func <Entity, KeyType> > GetLambda(ExecuteGroupByStage groupByStage)
{
return(Expression.Lambda <Func <Entity, KeyType> >(groupByStage.Expression, groupByStage.ParameterExpression));
}
public abstract ValueTask <IQueryable <IGrouping <KeyType, Entity> > > ExecuteGroupBy(IQueryable <Entity> queryable, ExecuteGroupByStage groupByStage);
public async ValueTask <IQueryable> Execute(IQueryable queryable, ExecuteGroupByStage groupByStage)
{
return(await ExecuteGroupBy((IQueryable <Entity>) queryable, groupByStage));
}
public override ValueTask <IQueryable <IGrouping <KeyType, Entity> > > ExecuteGroupBy(IQueryable <Entity> queryable, ExecuteGroupByStage groupByStage)
{
return(new ValueTask <IQueryable <IGrouping <KeyType, Entity> > >(queryable.GroupBy(GetLambda(groupByStage))));
}