Add Proddate(manufactureDate) from inventbatch table in Onhandlist form


I am trying to add proddate field on onhandlist form extending InventSum table and add display method like below

public static display InventBatchProddate ProdDate(InventSum _this)


InventBatch inventBatch;

select prodDate from inventBatch where inventbatch.itemId == +this.ItemId;

return invetBatch.ProdDate;


This is returning only first date from database for each item its not giving correct prod date. so i need to join my select statement with InventDim to get correct proddate. Can anyone tell me how to join inventdim to above query so that it returns correct proddates.