markonly and calcsum

With the MARK + MARKEDONLY, the calcsums does not work.

To use a SIFT-field, you make a record-var on the table of the SIFT-field (lets take Quantity in Item Ledger Entry) to make a sum of the different records.
Then you have to put the filters on the record-variable to indicate which records you want to use for the sum.
e.g.

recItemLedgerEntry.RESET;
recItemLedgerEntry.SETCURRENTKEY("Item No.");
recItemLedgerEntry.SETRANGE("Item No.",'1000'); //take only records of item 1000.
recItemLedgerEntry.CALCSUMS(Quantity); // total Quantity of records of item 1000.
MESSAGE('The inventory=%1',recItemLedgerEntry.Quantity);

Remark1: remember the recSomeTable.CALCSUMS("some field") will OVERWRITE the current value in "some field" of table "recSomeTable".

Remark2:In table "Item Ledger Entry",in some index starting with "Item No." you need to define Quantity as SumIndexField.

Remark3: the value of my example can also be obtained with field "Inventory" of table 27:"Item".