數據庫創建不能正常工作的android

我是Windows Phone的開發者和新的Android數據庫，我無法創造的Android 本地分貝我無法明白的地方我做錯了數據庫創建不能正常工作的android

我會被存儲我的數據庫中的一些數據，然後將獲取它填充我的列表視圖。

目前，我無法創建一個樣本數據庫，下面是我的代碼

public final class DbContract { 

public DbContract() { 
} 

private static final String TEXT_TYPE = " TEXT"; 
private static final String COMMA_SEP = ","; 
private static DatabaseHelper dbHandler; 
Context context; 

public DatabaseHelper database; 

/* Inner classes that defines the all table contents */ 

/** 
* Hospital database structure, query 
* */ 

public static abstract class Hospital implements BaseColumns { 
    public static final String TABLE_NAME = "emergency_hospital"; 
    public static final String HOSPITAL_NAME = "name"; 
    public static final String HOSPITAL_ADDRESS = "address"; 
    public static final String HOSPITAL_CONTACT_NUMBER = "number"; 

} 

private static final String SQL_CREATE_EMERGENCY_HOSPITAL = "CREATE TABLE " 
     + Hospital.TABLE_NAME + " (" + Hospital._ID 
     + " INTEGER PRIMARY KEY," + Hospital.HOSPITAL_NAME + TEXT_TYPE 
     + COMMA_SEP + Hospital.HOSPITAL_ADDRESS + TEXT_TYPE + COMMA_SEP 
     + Hospital.HOSPITAL_CONTACT_NUMBER + TEXT_TYPE + COMMA_SEP + ");"; 

private static final String SQL_DELETE_EMERGENCY_HOSPITAL = "DROP TABLE IF EXISTS " 
     + Hospital.TABLE_NAME; 

/** 
* Handles database versions, create and populate tables in database 
**/ 

public class DatabaseHelper extends SQLiteOpenHelper { 

    public static final int DATABASE_VERSION = 1; 
    public static final String DATABASE_NAME = "sample.db"; 

    public DatabaseHelper(Context context) { 
     super(context, DATABASE_NAME, null, DATABASE_VERSION); 
    } 

    public void onCreate(SQLiteDatabase db) { 
     db.execSQL(SQL_CREATE_EMERGENCY_HOSPITAL); 
    } 

    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { 
     // This database is only a cache for online data, so its upgrade 
     // policy is 
     // to simply to discard the whole database and start over 
     db.execSQL(SQL_DELETE_EMERGENCY_HOSPITAL); 
     onCreate(db); 
    } 


} 

public static DatabaseHelper getDbHandler() { 
    return dbHandler; 
} 

public void HospitalData() { 
    // Gets the data repository in write mode 
    SQLiteDatabase db = database.getWritableDatabase(); 

    // Create a new map of values, where column names are the keys 
    ContentValues values = new ContentValues(); 

    values.put(Hospital.HOSPITAL_NAME, "Bellevue Hospital Centre"); 
    values.put(Hospital.HOSPITAL_ADDRESS, "Manhattan"); 
    values.put(Hospital.HOSPITAL_CONTACT_NUMBER, "4356754"); 

    // Insert the new row, returning the primary key value of the new row 
    long newRowId; 

    newRowId = db.insert(Hospital.TABLE_NAME, null, values); 
} 

}

在我的主要活動是

private static DatabaseHelper dbHelper; 
private SQLiteDatabase db; 
dbHelper = DbContract.getDbHandler(); 
    db = dbHelper.getReadableDatabase();

我的清單說：

<provider 
     android:name=".database.DbContract" 
     android:authorities="com.demo" > 
    </provider>

這是初始化數據庫創建的正確方法嗎？

E/AndroidRuntime(2069): java.lang.RuntimeException: Unable to get provider com.demo.database.DbContract: java.lang.ClassCastException: com.demo.database.DbContract cannot be cast to android.content.ContentProvider 

E/AndroidRuntime(2069): at   com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694) 
    E/AndroidRuntime(2069): Caused by: java.lang.ClassCastException:  com.demo.database.DbContract cannot be cast to android.content.ContentProvider

謝謝！

來源

2014-11-15 MobiDev

你有什麼錯誤嗎？ –

其實你寫錯了查詢...首先你必須糾正它... –

我已經添加了日誌可以請你檢查 – MobiDev

您的mainfest文件具有名稱爲「.database.DbContract」的提供程序標記。這是你得到異常的根本原因。提供者標籤用於聲明內容提供者，名稱標籤可以是內容提供者的包名稱，但在您的情況下，它不是任何內容提供者子類的名稱。因此得到類拋出異常。請閱讀內容提供者的基本知識： http://developer.android.com/guide/topics/providers/content-provider-basics.html

希望它能幫助你！

來源

2014-11-15 16:51:18

數據庫創建不能正常工作的android

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