internal static bool HasAggregates(SelectExpression expression) { AggregateChecker checker = new AggregateChecker(); checker.Visit(expression); return(checker._hasAggregate); }
private static bool CanMergeWithFrom(SelectExpression select, bool isTopLevel) { SelectExpression fromSelect = GetLeftMostSelect(select.From); if (fromSelect == null) { return(false); } //if (!IsColumnProjection(fromSelect)) return false; bool selHasNameMapProjection = IsNameMapProjection(select); bool selHasOrderBy = select.OrderBy != null && select.OrderBy.Count > 0; bool selHasGroupBy = select.GroupBy != null && select.GroupBy.Count > 0; bool selHasAggregates = AggregateChecker.HasAggregates(select); bool selHasJoin = select.From is JoinExpression; bool frmHasOrderBy = fromSelect.OrderBy != null && fromSelect.OrderBy.Count > 0; bool frmHasGroupBy = fromSelect.GroupBy != null && fromSelect.GroupBy.Count > 0; bool frmHasAggregates = AggregateChecker.HasAggregates(fromSelect); // both cannot have orderby if (selHasOrderBy && frmHasOrderBy) { return(false); } // both cannot have groupby if (selHasGroupBy && frmHasGroupBy) { return(false); } // cannot move forward order-by if outer has group-by if (frmHasOrderBy && (selHasGroupBy || selHasAggregates || select.IsDistinct)) { return(false); } // cannot move forward a limit or an offset if outer has distinct if (fromSelect.Limit != null && fromSelect.Offset != null && (select.IsDistinct || selHasAggregates || selHasGroupBy || selHasJoin)) { return(false); } // cannot move forward a distinct if outer has groupby or a different projection if (fromSelect.IsDistinct && (!selHasNameMapProjection || selHasGroupBy || selHasAggregates || (selHasOrderBy && !isTopLevel) || selHasJoin)) { return(false); } if (frmHasAggregates && (select.IsDistinct || selHasAggregates || selHasGroupBy || selHasJoin)) { return(false); } return(true); }