Using select() and join() you can specify only the properties you wish to fetch.

This can be a very significant performance benefit by only fetching the properties you need. This is more obvious on wider objects. This is also a design benefit in that it removes the "fixed" design constraints of using secondary table properties.

// a partial object query
// ... only fetch the order id, orderDate and shipDate
List<Order> orders = 
	Ebean.find(Order.class)
		.select("orderDate, shipDate")
		.findList();

Note: the Id property is always fetched even if you do not explicitly include it in the list of properties you want to fetch

<sql summary='[app.data.test.Order]'>
select o.id, o.order_date, o.ship_date 
from or_order o
<sql>

*ANY* node of the object graph can be a partial object. In this case both the order and the customer are partially populated.

// a partial object query
// ... only fetch the order id, orderDate and shipDate
// ... only fetch the name of the customer
List<Order> orders = 
	Ebean.find(Order.class)
		.select("orderDate, shipDate")
		.join("customer","name")
		.findList();

<sql summary='[app.data.test.Order, customer]'>
select o.id, o.order_date, o.ship_date
        , c.id, c.name 
from or_order o
join or_customer c on o.customer_id = c.id 
<sql>

With this example note that the Product associated with each order detail is partially populated (fetching the product id, sku and name).

... again, *ANY* node in the object graph can be partially populated no matter how deep it is in the object graph.

// a mix of partial objects and fully populated objects
List<Order> orders = 
	Ebean.find(Order.class)
		.select("orderDate, shipDate")  // partial
		.join("customer","name")  // partial
		.join("customer.shippingAddress") 
		.join("details")                  
		.join("details.product","sku,name") // partial
		.findList();

<sql summary='[app.data.test.Order, customer, customer.shippingAddress]
--               +many[details, details.product]'>
select o.id, o.order_date, o.ship_date
        , c.id, c.name
        , ca.id, ca.line_1, ca.line_2, ca.city, ca.region, ca.cretime, ca.updtime, ca.country_code
        , d.id, d.order_qty, d.ship_qty, d.cretime, d.updtime, d.order_id
        , dp.id, dp.sku, dp.name 
from or_order o
join or_customer c on o.customer_id = c.id 
left outer join or_address ca on c.shipping_address_id = ca.id 
left outer join or_order_detail d on o.id = d.order_id 
left outer join or_product dp on d.product_id = dp.id  
order by o.id
<sql>