Mig-infocom MiG Calendar DBConnect Guide Manual de usuario descargar pdf (Pagina 22)

MiG InfoCom AB

calling PropertyKey.getKey(“myPropertyName”). The key

returned can be used to store any property in any

PropertyConsumer (which both the Activity and Category

classes implement).

When you have stored your value(s) they are as easy as any built in

property to persist. You only have to create a property mapping as

explained above. If the value yo want to store is of a type that is

unknown to DCConnect, such as your own defined classes, those can

be persisted as well and this is explained in the next section.

Persisting your custom data types

To persist a property in the Activity or Category that has a class type

that is a bit more complex than for instance String, Integer or

Long you will have to create your own PropertyMapping sub

class. It is used to convert to and from the custom class type and a

type that is recognized by the database, which normally means

String, Integer or Long.

There are two ways to go about this. Use a String to store the

object in the backing store or to map the custom type to two or more

fields in the backing store (e.g. columns in a database).

Note! It is currently not possible for an Activity or Category to have

the ID object stored in more than one database column. The ID can

be a custom class type but it has to be stored in a single field

(column) in the database. Put in another way, the the primary key of

the record can not be more than one column.

The abstract methods in PropertyMapping are easy to

understand how to implement given the API JavaDoc. Here is a

straight forward implementation of a property mapping that writes and

reads a type MyComplexType that holds two integers.

DBConnect Guide Page 22 / 25

1 2 ... 17 18 19 20 21 22 23 24 25

Sin comentarios

Mig-infocom MiG Calendar DBConnect Guide Manual de usuario Pagina 22