How to Range or filter your Data's on your form

Example :

You have a form with datasource : Custtable.

and youwant to show only "v000001"

Override your Custtable.ExecuteQuery with your code, before Super().

CustTable_ds.query().dataSourceTable(tableNum(CustTable)).addRange(fieldNum(CustTable, CustId)).value(queryValue('v000001'));

see the detail in ":

https://hellodax.com/2014/12/03/add-filter-to-form-datasource-methodexecutequery-example-code/