ORMLite不能创建第二个表格

我分析的数据来自JSON到对应的类数据并希望将其保存在ORMLite ......在这里我的班ORMLite不能创建第二个表格

public class Categories { 
    ArrayList<Category> categories; 

    public Categories() { 
     categories = new ArrayList<Category>(); 
    } 

     public ArrayList<Category> getCategories() { 
      return this.categories; 
    } 
}

和级别：

@DatabaseTable(tableName = "levels") 
public class Level { 
    @SerializedName("id") 
    @DatabaseField(id = true) 
    int id; 

    @SerializedName("title") 
    @DatabaseField(dataType = DataType.STRING) 
    String title; 

    public Level() { } 

    public Level(int id, String title) { 
     this.id = id; 
     this.title = title; 
    } 
}

在数据库处理器类

onCreate方法：

@Override 
public void onCreate(SQLiteDatabase db, ConnectionSource connectionSource) { 
    try { 
     TableUtils.createTable(connectionSource, Category.class); 
     TableUtils.createTable(connectionSource, Level.class); 
    } catch (SQLException e){ 
     Log.e(TAG, "error creating DB " + DATABASE_NAME); 
     throw new RuntimeException(e); 
    } 
}

和DAO方法在数据库处理器：

public Dao<Category, Integer> getCategoryDao() throws SQLException { 
    if (simpleCategoryDao == null) { 
     simpleCategoryDao = getDao(Category.class); 
    } 
    return simpleCategoryDao; 
} 

    public Dao<Level, Integer> getLevelDao() throws SQLException { 
     if (simpleLevelDao == null) { 
      simpleLevelDao = getDao(Level.class); 
     } 
     return simpleLevelDao; 
    } 

    public RuntimeExceptionDao<Category, Integer> getSimpleCategoryDao() { 
     if (categoryRuntimeDao == null) { 
      categoryRuntimeDao = getRuntimeExceptionDao(Category.class); 
     } 
     return categoryRuntimeDao; 
    } 

    public RuntimeExceptionDao<Level, Integer> getSimpleLevelDao() { 
     if (levelRuntimeDao == null) { 
      levelRuntimeDao = getRuntimeExceptionDao(Level.class); 
     } 
     return levelRuntimeDao; 
    }

我解析来自JSON我的数据在我的活动那样：

DatabaseHandler db = new DatabaseHandler(getApplicationContext()); 
    JSONObject data = json.getJSONObject(KEY_DATA); 
    // getting categories 
    JSONArray categories = new JSONArray(); 
    categories = data.getJSONArray(KEY_CATEGORIES); 
    Gson gson = new Gson(); 
     JsonParser parser = new JsonParser(); 
     JsonArray array = parser.parse(categories.toString()).getAsJsonArray(); 
     Type listType = new TypeToken<List<Category>>() {}.getType(); 
     List<Category> tasks = new ArrayList<Category>(); 
     tasks = gson.fromJson(array.toString(), listType); 
     RuntimeExceptionDao<Category, Integer> simpleDao = getHelper1().getSimpleCategoryDao(); 
     Dao<Category, Integer> categoryDao = databaseHandler.getCategoryDao(); 
     Log.i("categoryDAO",categoryDao.queryForAll().toString()); 

    // getting levels 
    JSONArray jsonlevels =new JSONArray(); 
    jsonlevels = data.getJSONArray(KEY_LEVELS); 
    JsonArray levelsarray = parser.parse(jsonlevels.toString()).getAsJsonArray(); 
    Type listlevels = new TypeToken<List<Level>>() {}.getType(); 
    List<Level> levels = new ArrayList<Level>(); 
    levels = gson.fromJson(levelsarray.toString(), listlevels); 
    Log.i("levelsgson",levels.toString()); 
    RuntimeExceptionDao<Level, Integer> levelDao = getHelper1().getSimpleLevelDao(); 
    Log.i("levelDAO",levelDao.toString()); 
    Dao<Level, Integer> levelsDao = databaseHandler.getLevelDao(); 
    Log.i("levelsDAO",levelsDao.queryForId(3).toString());

我得到分类数据successfuly，但想打电话queryForId（）的级别DAO例如，当我有例外。有这样的例外：

java.sql.SQLException: queryForOne from database failed: SELECT * FROM `levels` WHERE `id` = ? 
    at com.j256.ormlite.misc.SqlExceptionUtil.create(SqlExceptionUtil.java:22) 
    at com.j256.ormlite.android.AndroidDatabaseConnection.queryForOne(AndroidDatabaseConnection.java:169) 

at com.j256.ormlite.stmt.mapped.MappedQueryForId.execute(MappedQueryForId.java:38) 
at com.j256.ormlite.stmt.StatementExecutor.queryForId(StatementExecutor.java:84) 
at com.j256.ormlite.dao.BaseDaoImpl.queryForId(BaseDaoImpl.java:219) 
at com.assignmentexpert.LoginActivity$1.onClick(LoginActivity.java:119) 
at android.view.View.performClick(View.java:2485) 
at android.view.View$PerformClick.run(View.java:9080) 
at android.os.Handler.handleCallback(Handler.java:587) 
at android.os.Handler.dispatchMessage(Handler.java:92) 
at android.os.Looper.loop(Looper.java:123) 
at android.app.ActivityThread.main(ActivityThread.java:3687) 
at java.lang.reflect.Method.invokeNative(Native Method) 
at java.lang.reflect.Method.invoke(Method.java:507) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:867) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:625) 
at dalvik.system.NativeStart.main(Native Method) 
     Caused by: android.database.sqlite.SQLiteException: no such table: levels: , while compiling: SELECT * FROM `levels` WHERE `id` = ? 
at android.database.sqlite.SQLiteCompiledSql.native_compile(Native Method) 
at android.database.sqlite.SQLiteCompiledSql.compile(SQLiteCompiledSql.java:92) 
at android.database.sqlite.SQLiteCompiledSql.<init>(SQLiteCompiledSql.java:65) 
at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:83) 
at android.database.sqlite.SQLiteQuery.<init>(SQLiteQuery.java:49) 
at android.database.sqlite.SQLiteDirectCursorDriver.query(SQLiteDirectCursorDriver.java:42) 
at android.database.sqlite.SQLiteDatabase.rawQueryWithFactory(SQLiteDatabase.java:1356) 
at android.database.sqlite.SQLiteDatabase.rawQuery(SQLiteDatabase.java:1324) 
at com.j256.ormlite.android.AndroidDatabaseConnection.queryForOne(AndroidDatabaseConnection.java:155) 
... 15 more

所以问题是，“层次”表不能创造。不明白为什么，如果我用平等机制作为分类表..

经过一番分析我明白，问题是这种方法

public void saveContacts(List<Category> contacts) throws SQLException 
    { 

     OrmLiteSqliteOpenHelper dbHelper= DatabaseHandler.getInstance(_context); 
     Dao<Category, Integer> daoContact=dbHelper.getDao(Category.class); 

     QueryBuilder<Category, Integer> queryBuilder = daoContact.queryBuilder(); 
     Log.i("dao",queryBuilder.selectColumns("title").prepare().toString()); 


     for (Category contact : contacts) { 
      Log.i("dao",contact.toString()); 
      HelperFactory.GetHelper().getCategoryDao().create(contact); 
     } 

    }

在创建（）一行。它抛出这样的一组异常为：

FATAL EXCEPTION: main 
java.lang.NullPointerException 
    at com.library.DataParsing.saveContacts(DataParsing.java:61) 
    at com.library.DataParsing.fillCategories(DataParsing.java:45) 
    at com.library.DatabaseHandler.onCreate(DatabaseHandler.java:85) 
    at com.j256.ormlite.android.apptools.OrmLiteSqliteOpenHelper.onCreate(OrmLiteSqliteOpenHelper.java:169) 
    at android.database.sqlite.SQLiteOpenHelper.getWritableDatabase(SQLiteOpenHelper.java:126) 
at com.j256.ormlite.android.AndroidConnectionSource.getReadWriteConnection(AndroidConnectionSource.java:63) 
    at com.j256.ormlite.android.AndroidConnectionSource.getReadOnlyConnection(AndroidConnectionSource.java:51) 
    at com.j256.ormlite.stmt.StatementExecutor.buildIterator(StatementExecutor.java:202) 
    at com.j256.ormlite.stmt.StatementExecutor.query(StatementExecutor.java:155) 
    at com.j256.ormlite.stmt.StatementExecutor.queryForAll(StatementExecutor.java:113) 
    at com.j256.ormlite.dao.BaseDaoImpl.queryForAll(BaseDaoImpl.java:237) 
    at com.assignmentexpert.LoginActivity$1.onClick(LoginActivity.java:97) 
at android.view.View.performClick(View.java:2485) 
    at android.view.View$PerformClick.run(View.java:9080) 
    at android.os.Handler.handleCallback(Handler.java:587) 
    at android.os.Handler.dispatchMessage(Handler.java:92) 
    at android.os.Looper.loop(Looper.java:123) 
    at android.app.ActivityThread.main(ActivityThread.java:3687) 
    at java.lang.reflect.Method.invokeNative(Native Method) 
    at java.lang.reflect.Method.invoke(Method.java:507) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:867) 
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:625) 
    at dalvik.system.NativeStart.main(Native Method)

帮助它，请...

来源

2012-07-31 Rikki Tikki Tavi

你应该接受你的答案。 – Gray 2012-09-26 20:37:29

问题解决了将上下文传递给从OrmLiteSqliteOpenHelper扩展的DatabaseHandler。

来源

2012-08-14 08:49:08

所以，当你的应用程序运行在第一次的onCreate()方法被调用。如果您在以后的日期添加levels表（或修改其模式），则需要增加数据库版本，以便可以调用onUpgrade()。

您可以从主页ORMLite的Android examples中看到典型的帮助模式。这是source code for the helper。在你的帮手中需要像下面这样的东西。

// any time you make changes to your database objects, you may have to increase 
// the database version 
private static final int DATABASE_VERSION = 2; 
... 

@Override 
public void onUpgrade(SQLiteDatabase db, ConnectionSource connectionSource, 
    int oldVersion, int newVersion) { 
    try { 
     Log.i(DatabaseHelper.class.getName(), "onUpgrade"); 
     TableUtils.dropTable(connectionSource, SimpleData.class, true); 
     // after we drop the old databases, we create the new ones 
     onCreate(db, connectionSource); 
    } catch (SQLException e) { 
     Log.e(DatabaseHelper.class.getName(), "Can't drop databases", e); 
     throw new RuntimeException(e); 
    } 
}

来源

2012-07-31 14:49:44 Gray

ORMLite不能创建第二个表格

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