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休眠映射<key,set<value>>

hibernate-mapping hibernate java

2

Dejell · 技术社区 · 14 年前

我有以下表格:

@Entity
@Table(name = "events")    
Event
    --id
    --name

@Entity
@Table(name = "state")    
State
    --id
    --name

@Entity
@Table(name = "action")    
Action
    --id
    --name
@Entity
@Table(name = "state_event_action")
    StateEventAction
--id
--state_id
--event_id
--action_id

我想进去 state 类获取 map<key, set<value>> 属于 Map<Event, set<StateEventAction>>

冬眠时我该怎么做?

3 回复 | 直到 14 年前

1

2

Igor Grinfeld 14 年前

@Entity 
@Table(name = "state_event_action") 
StateEventAction 
--id 
--state_id 
--event_id 
--Set<action> actions

@Entity @Table(name = "state")     
State 
    --id 
    --name 
 Map<Event,StateEventAction> eventActions;

2

6

Pascal Thivent 14 年前

map<key, Set<value>> Map<Event, Set<StateEventAction>>

UserCollectionType blog post MultiMap

Multimap

3

1

3urdoch 14 年前

State state = // < the state object;
Query q = Session.createQuery("from StateEventAction sea inner join fetch sea.event where sea.state = :state");
q.setEntity("state", state);

Map<Event, Set<StateEventAction>> map = new HashMap<Event, Set<StateEventAction>>();

for(Iterator itr = q.list().iterator(); itr.hasNext();) {
   StateEventAction sea = itr.next();
   Event event = sea.getEvent();
   Set<StateEventAction> theSet = map.get(event);
   if(theSet == null) {
      theSet = new HashSet<StateEventAction>();
      map.put(event, theSet);
   }
   theSet.add(sea);
}