While Loop insteads of many nested selects -

Trying to loop instead of several nested selections:

  Table A ID ItemID 1 12 2 13 3 14 4 15 5 16 6 17 11 19 Table B Bid Item ID 8 10 7 11 6 12 9 13 10 14 11 17 BITMID A After getting the BID, after getting the BID, I will be able to return to the AID relevant A. To get ATMD back to this BBI need to get the next BITMAID, and so long as the BID is not fired 
 
 For example table AID1 (Item IDID12) BID 6 to get BITMID 12, this item will link back to Table A ID 6 to get IDID 17, it will be linked from the table B. To get Item IDID1 for item ID 17 Back to Table A for To get the BID 11, to do this, and unless the BID is zero 
 
 This 10-15 level can be deep, so the nested selection is not dynamic enough, so I Need to get it in the loop 
 
 Any thoughts please ??