Passing the Key in $expand Option
Here is my ODATA Service link.
By Passing the Work Order type as '36'. I will get the Order details ( ZORDDATA Custom Table ) and Order Part Details ( ZORDPART table)
For a Single Order . there will be multiple parts. So I use the $Expand to get the Order part details ( Work type will be the Key)
Now If I the User does not pass the Work type (or value as '' or blank) , I wont get any Part details though I will get other order details from ZORDDATA table.
Now the Requirement : I need to Fetch the Order type from ZORDDATA and Pass it to ZORDPART and get part details without directly passing the Work type field in the ODATA Service,