Je ne peux pas obtenir les valeurs de la table. Relation un à plusieurs

Question

Salut j'ai un problème avec obtenir de nombreux enregistrements de db c'est ma table principale

@DatabaseTable(tableName = "MyTrips") 
public class MyTripTable { 

@DatabaseField(generatedId = true) 
private long id; 

@DatabaseField 
private long timestamp; 


@DatabaseField(foreign = true, foreignAutoRefresh = true) 
private ForeignCollection<PortTable> mPorts; 

public MyTripTable() {} 

public ForeignCollection<PortTable> getPorts() { 
    return mPorts; 
} 

public long getId() { 
    return id; 
} 
} 

et voici deuxième table

@DatabaseTable(tableName = "Ports") 
public class PortTable { 

@DatabaseField(generatedId = true) 
private long id; 

@DatabaseField 
private long timestamp; 

@DatabaseField(foreign = true, foreignAutoRefresh = true) 
private MyTripTable myTripTable; 

public PortTable() {} 
public void setTripAssigned(MyTripTable myTripTable){ 
    this.myTripTable = myTripTable; 
} 
} 

Et je besoin d'un MyTrips ont plus Ports Je le fais par example mais ne fonctionne pas

problème est ici:

private void strawberry(){ 
    DatabaseHelper helper = OpenHelperManager.getHelper(getApplicationContext(), DatabaseHelper.class); 
    RuntimeExceptionDao<MyTripTable, Long> mTrip = helper.getTripRuntimeExcaptionDao(); 
    RuntimeExceptionDao<PortTable, Long> mPort = helper.getPortRuntimeExcaptionDao(); 

    long time1 = Calendar.getInstance().getTimeInMillis(); 

    //crate data 
    MyTripTable myFirstTrip = new MyTripTable(153315, "Praha - Gothenburg",  "Big fat woman", 
      time1,time1,time1,time1,1,5,6); 
    mTrip.create(myFirstTrip); 

    PortTable port1 = new PortTable("Praha", 
      "Praha is the capital and largest city of the Czech Republic. ", 
      50.078047, 
      14.427172); 
    port1.setTripAssigned(myFirstTrip); 
    PortTable port2 = new PortTable("Praha", 
      "Praha is the capital and largest city of the Czech Republic. ", 
      50.078047, 
      14.427172); 
    port2.setTripAssigned(myFirstTrip); 
    PortTable port3 = new PortTable("Praha", 
      "Praha is the capital and largest city of the Czech Republic. ", 
      50.078047, 
      14.427172); 
    port3.setTripAssigned(myFirstTrip); 
    PortTable port4 = new PortTable("Praha", 
      "Praha is the capital and largest city of the Czech Republic. ", 
      50.078047, 
      14.427172); 
    port4.setTripAssigned(myFirstTrip); 

    mPort.create(port1); 
    mPort.create(port2); 
    mPort.create(port3); 
    mPort.create(port4); 


    //Get data 
    Log.e("LSA", "----------------------------------TRIPS"); 
    List<MyTripTable> alltrips = mTrip.queryForAll(); 
    Log.e("LSA", "TRIPS" + alltrips.toString()); 
    for (MyTripTable trip : alltrips){ 
     Log.e("LSA", "Trip: " + trip.toString()); 
    } 

    Log.e("LSA", "----------------------------------PORTS"); 
    List<PortTable> allPorts = mPort.queryForAll(); 
    Log.e("LSA", "PORTS" + allPorts.toString()); 
    for (PortTable port : allPorts){ 
     Log.e("LSA", "port: " + port.toString()); 
    } 

    Log.e("LSA", "----------------------------------PORTs assigned"); 

    MyTripTable mOneTrip = mTrip.queryForId(myFirstTrip.getId()); 
    ForeignCollection<PortTable> mPortsForOneTrip = mOneTrip.getPorts(); 

    Log.e("LSA", "ports inside trip: " + mPortsForOneTrip); 
    } 

cette partie retourne toujours null

ForeignCollection<PortTable> mPortsForOneTrip = mOneTrip.getPorts(); 

Pouvez-vous me aider? Où est une erreur? Merci pour la réponse!

Answer 1

Fondamentalement, votre méthode principale devrait vous donner l'erreur ci-dessous sur l'exécution du code ci-dessus. Je ne suis pas sûr de savoir pourquoi cela fonctionne pour vous en premier lieu.

Exception in thread "main" java.sql.SQLException: Field 'mPorts' in class interface com.j256.ormlite.dao.ForeignCollection' should use the @ForeignCollectionField annotation not foreign=true

L'erreur ci-dessus dit dans votre classe MyTripTable.java, vous avez marqué @DatabaseField (étranger = true, foreignAutoRefresh = true) sur une collection, alors que, selon docs, vous devez utiliser la @ForeignCollectionField d'annotation. Je poste le code de fonctionnement.

Code pour MyTripTable.java

@DatabaseTable(tableName = "MyTrips") 
public class MyTripTable { 

    @DatabaseField(generatedId = true) 
    private long id; 

    @DatabaseField 
    private long timestamp; 

// @DatabaseField(foreignAutoRefresh = true) 
    @ForeignCollectionField(eager = false) 
    private ForeignCollection<PortTable> mPorts; 

    public MyTripTable() { 
    } 

    public ForeignCollection<PortTable> getPorts() { 
     return mPorts; 
    } 

    public long getId() { 
     return id; 
    } 

    public long getTimestamp() { 
     return timestamp; 
    } 

    public void setId(long id) { 
     this.id = id; 
    } 

    public void setTimestamp(long timestamp) { 
     this.timestamp = timestamp; 
    } 
} 

Code pour Port Table.java

@DatabaseTable(tableName = "Ports") 
public class PortTable { 

    /** The id. */ 
    @DatabaseField(generatedId = true) 
    private long id; 

    /** The timestamp. */ 
    @DatabaseField 
    private long timestamp; 

    /** The my trip table. */ 
    @DatabaseField(foreign = true, foreignAutoRefresh = true) 
    private MyTripTable myTripTable; 

    /** 
    * Instantiates a new port table. 
    */ 
    public PortTable() { 
    } 

    /** 
    * Sets the trip assigned. 
    * 
    * @param myTripTable the new trip assigned 
    */ 
    public void setTripAssigned(MyTripTable myTripTable) { 
     this.myTripTable = myTripTable; 
    } 

    /** 
    * Gets the id. 
    * 
    * @return the id 
    */ 
    public long getId() { 
     return id; 
    } 

    /** 
    * Gets the timestamp. 
    * 
    * @return the timestamp 
    */ 
    public long getTimestamp() { 
     return timestamp; 
    } 

    /** 
    * Sets the id. 
    * 
    * @param id the new id 
    */ 
    public void setId(long id) { 
     this.id = id; 
    } 

    /** 
    * Sets the timestamp. 
    * 
    * @param timestamp the new timestamp 
    */ 
    public void setTimestamp(long timestamp) { 
     this.timestamp = timestamp; 
    } 
} 

ci-dessous montre l'exécution de code ci-dessus ....

public static void main(String[] args) throws SQLException { 
     String databaseUrl = "jdbc:mysql://localhost:3306/YOUR_DATABASE"; 

     ConnectionSource connectionSource = new JdbcConnectionSource(databaseUrl, "root", "root"); 
     // instantiate the dao 
     Dao<MyTripTable, Long> tripDao = DaoManager.createDao(connectionSource, MyTripTable.class); 
     Dao<PortTable, Long> portDao = DaoManager.createDao(connectionSource, PortTable.class); 

     // if you need to create the 'accounts' table make this call 
     TableUtils.createTable(connectionSource, MyTripTable.class); 
     TableUtils.createTable(connectionSource, PortTable.class); 

     long time1 = Calendar.getInstance().getTimeInMillis(); 

     // crate data 
     MyTripTable myFirstTrip = new MyTripTable(); 
     myFirstTrip.setTimestamp(time1); 

     tripDao.create(myFirstTrip); 

     PortTable port1 = new PortTable(); 
     port1.setTimestamp(time1); 
     port1.setTripAssigned(myFirstTrip); 

     PortTable port2 = new PortTable(); 
     port2.setTimestamp(time1); 
     port2.setTripAssigned(myFirstTrip); 

     PortTable port3 = new PortTable(); 
     port3.setTimestamp(time1); 
     port3.setTripAssigned(myFirstTrip); 

     portDao.create(port1); 
     portDao.create(port2); 
     portDao.create(port3); 

     List<MyTripTable> alltrips = tripDao.queryForAll(); 
     for (MyTripTable trip : alltrips) { 
      System.out.println(trip); 
     } 

     List<PortTable> allPorts = portDao.queryForAll(); 
     for (PortTable port : allPorts) { 
      System.out.println(port); 
     } 

     MyTripTable mOneTrip = tripDao.queryForId(myFirstTrip.getId()); 
     ForeignCollection<PortTable> mPortsForOneTrip = mOneTrip.getPorts(); 
     System.out.println(mPortsForOneTrip); 

    } 

J'ai testé la ci-dessus le code et il fonctionnait bien. S'il vous plaît laissez-moi savoir si vous faites face à d'autres problèmes.