Get data from Different table.

I have 4 tables TableA,TableB,TableC,TableD

TableD has relation with other 3 tables.

TableC has relation with TableB.

I have created one form. In that Form I should display the data from the TableA,TableB,TableC, based on one field which is in TableA.

TableA data displayed in Form using
qbdsItemRequest.addRange(fieldnum(TableA,TableAField1)).value(StringEdit.valueStr());

How to get data from TableB,TableC…? TableA dont have relation between TableB,TableC…

How do you want to join or link TableA and TableB if they aren’t related to each other?

If has relation means, How to get?

Would you mind to elaborate your question a little bit?