com.avaje.ebean.overview.html Maven / Gradle / Ivy
Ebean API
Ebean Object Relational Mapping (start at
EbeanServer or Ebean).
Ebean
Provides the main API for fetching and persisting beans with Ebean.
For a full description of the query language refer to Query.
EXAMPLE 1: Simple fetch
{@code
// fetch order 10
Order order = Ebean.find(Order.class, 10);
}
EXAMPLE 2: Fetch an Object with associations
{@code
// fetch Customer 7 including their billing and shipping addresses
Customer customer = Ebean.find(Customer.class)
.fetch("billingAddress");
.fetch("shippingAddress");
.setId(7)
.findUnique();
Address billAddr = customer.getBillingAddress();
Address shipAddr = customer.getShippingAddress();
}
EXAMPLE 3: Fetch a list of Objects with associations
{@code
// Note: This example shows a "Partial Object".
// For the product objects associated with the
// order details only the product id and name is
// fetched (the product objects are partially populated).
// fetch orders for customer.id = 2
List orderList = Ebean.find(Order.class);
.fetch("customer")
.fetch("customer.shippingAddress")
.fetch("details")
.fetch("details.product","name")
.where().eq("customer.id",2)
.findList();
// Note: Only the product id and name is fetched for the
// product details. This is referred to as a
// "Partial Object" (one that is partially populated).
// code that traverses the object graph...
Order order = orderList.get(0);
Customer customer = order.getCustomer();
Address shipAddr = customer.getShippingAddress();
List details = order.getDetails();
OrderDetail detail = details.get(0);
Product product = detail.getProduct();
String productName = product.getName();
}
EXAMPLE 4: Create and save an Order
{@code
// get a Customer reference so we don't hit the database
Customer custRef = Ebean.getReference(Customer.class, 7);
// create a new Order object
Order newOrder = new Order();
newOrder.setStatus(Order.Status.NEW);
newOrder.setCustomer(custRef);
ArrayList orderLines = new ArrayList();
newOrder.setLines(orderLines);
...
// add a line to the order
Product prodRef = Ebean.getReference(Product.class, 41);
OrderLine line = new OrderLine();
line.setProduct(prodRef);
line.setQuantity(10);
orderLines.add(line);
...
// save the order and its lines in a single transaction
// NB: assumes CascadeType.PERSIST is set on the order lines association
Ebean.save(newOrder);
}
EXAMPLE 5: Use another database
{@code
// Get access to the Human Resources EbeanServer/Database
EbeanServer hrServer = Ebean.getServer("HR");
// fetch contact 3 from the HR database
Contact contact = hrServer.find(Contact.class, 3);
contact.setStatus(Contact.Status.INACTIVE);
...
// save the contact back to the HR database
hrServer.save(contact);
}