我在我的Android应用程序中使用sqlite数据库。我在android中的数据库文件夹中预创建数据库。数据库已创建并在模拟器中正常工作，但当我在手机中运行相同的代码时，我会收到错误。
以下是有关如何在数据库文件夹中预创建数据库的代码。
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
SavingData.mainActivity = this;
try {
String destPath = "/data/data/" + getPackageName() + "/databases";
File f = new File(destPath);
if (!f.exists()) {
f.mkdirs();
f.createNewFile();
// ---copy the db from the assets folder into
// the databases folder---
CopyDB(getBaseContext().getAssets().open("exercisedatedb"),
new FileOutputStream(destPath + "/ExerciseDateDB"));
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
public void CopyDB(InputStream inputStream, OutputStream outputStream)
throws IOException {
// ---copy 1K bytes at a time---
byte[] buffer = new byte[1024];
int length;
while ((length = inputStream.read(buffer)) > 0) {
outputStream.write(buffer, 0, length);
}
inputStream.close();
outputStream.close();
}
}
以下是我得到的错误：
04-01 12:51:12.503: E/SQLiteLog(26823): (1) no such column: date
04-01 12:51:12.503: D/AndroidRuntime(26823): Shutting down VM
04-01 12:51:12.503: W/dalvikvm(26823): threadid=1: thread exiting with uncaught exception (group=0x40f722a0)
04-01 12:51:12.508: E/AndroidRuntime(26823): FATAL EXCEPTION: main
04-01 12:51:12.508: E/AndroidRuntime(26823): android.database.sqlite.SQLiteException: no such column: date (code 1): , while compiling: SELECT id, date FROM dates
04-01 12:51:12.508: E/AndroidRuntime(26823): at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method)
04-01 12:51:12.508: E/AndroidRuntime(26823): at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:1013)
04-01 12:51:12.508: E/AndroidRuntime(26823): at android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:624)
以下是我将数据插入数据库的方法：
public void insertDate(String date) {
// TODO Auto-generated method stub
db.open();
long id = db.insertDate(date);
db.close();
}
这是我的DBAdapter类：
public class DBAdapter {
static final String KEY_ROWID = "id";
static final String KEY_DATE = "date";
static final String TAG = "DBAdapter";
static final String DATABASE_NAME = "ExerciseDateDB";
static final String DATABASE_TABLE = "dates";
static final int DATABASE_VERSION = 1;
static final String DATABASE_CREATE = "create table dates (id integer primary key autoincrement, "
+ "date text not null);";
final Context context;
DatabaseHelper DBHelper;
SQLiteDatabase db;
public DBAdapter(Context ctx) {
this.context = ctx;
DBHelper = new DatabaseHelper(context);
}
private static class DatabaseHelper extends SQLiteOpenHelper {
DatabaseHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
try {
db.execSQL(DATABASE_CREATE);
} catch (SQLException e) {
e.printStackTrace();
}
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
Log.w(TAG, "Upgrading database from version " + oldVersion + " to "
+ newVersion + ", which will destroy all old data");
db.execSQL("DROP TABLE IF EXISTS contacts");
onCreate(db);
}
}
// ---opens the database---
public DBAdapter open() throws SQLException {
db = DBHelper.getWritableDatabase();
return this;
}
// ---closes the database---
public void close() {
DBHelper.close();
}
// ---insert a Date into the database---
public long insertDate(String date) {
ContentValues initialValues = new ContentValues();
initialValues.put(KEY_DATE, date);
return db.insert(DATABASE_TABLE, null, initialValues);
}
// ---deletes a particular date---
public boolean deleteDate(long rowId) {
return db.delete(DATABASE_TABLE, KEY_ROWID + "=" + rowId, null) > 0;
}
// ---retrieves all the score---
public Cursor getAllDate() {
return db.query(DATABASE_TABLE, new String[] { KEY_ROWID, KEY_DATE}, null, null, null, null, null);
}
// ---retrieves a particular score---
public Cursor getDate(long rowId) throws SQLException {
Cursor mCursor = db.query(true, DATABASE_TABLE, new String[] {
KEY_ROWID, KEY_DATE}, KEY_ROWID + "= " + rowId + "",
null, null, null, null, null);
if (mCursor != null) {
mCursor.moveToFirst();
}
return mCursor;
}
// ---updates a score---
public boolean updateDate(long rowId, String date) {
ContentValues args = new ContentValues();
args.put(KEY_DATE, date);
return db.update(DATABASE_TABLE, args, KEY_ROWID + "=" + rowId, null) > 0;
}
}
答案 0 :(得分：0)
这是我的数据库解决方案。它全部包含在一个类中。
太称之为语法是......
DatabaseManager mDatabase = DatabaseManager.getInstance（）;
公共类DatabaseManager {
private static DatabaseManager instance;
private final String DB_NAME = "singoff_database";
private final int DB_VERSION = 1;
private final String GAME_TABLE_NAME = "game_table";
private final String GAME_ID = "gameid";
private final String GAME_OPPONENT_ID = "opponent";
private final String GAME_TRACK = "track";
private final String GAME_FILE_PATH = "filepath";
private final String GAME_PICTURE = "picture";
private final String GAME_GUESSES = "guesses";
private final String GAME_DATE = "date";
private SQLiteDatabase mDb;
private Context context;
private DatabaseManager(Context context) {
this.context = context;
//create new or open database
DatabaseHelper helper = new DatabaseHelper(context);
this.mDb = helper.getWritableDatabase();
}
public synchronized static DatabaseManager getInstance() {
if (instance == null) {
Context context = Main.getInstance();
instance = new DatabaseManager(context);
}
return instance;
}
//__________________________________________________________________________________________//
//GAME LIST HANDLING STATEMENTS
public synchronized void addGame(String gID, String oID, String track,
String path, byte[] thumb, String datetime) {
ContentValues values = new ContentValues();
values.put(GAME_ID, gID);
values.put(GAME_OPPONENT_ID, oID);
values.put(GAME_TRACK, track);
values.put(GAME_FILE_PATH, path);
values.put(GAME_PICTURE, thumb);
values.put(GAME_DATE, datetime);
mDb.insert(GAME_TABLE_NAME, null, values);
}
public synchronized List<File> getGames() {
List<File> games = new ArrayList<File>();
Cursor cursor;
cursor = mDb.query(
GAME_TABLE_NAME,
new String[]{GAME_FILE_PATH},
null, null, null, null, null);
cursor.moveToFirst();
if (!cursor.isAfterLast()) {
do {
File file = new File(cursor.getString(0));
games.add(file);
} while (cursor.moveToNext());
}
cursor.close();
return games;
}
public synchronized Game getGame(String filepath) {
Cursor cursor;
//Game game = null;
Bitmap picture = null;
byte[] blob;
cursor = mDb.query(
GAME_TABLE_NAME,
new String[]{
GAME_OPPONENT_ID,
GAME_FILE_PATH,
GAME_PICTURE,
GAME_DATE},
GAME_FILE_PATH + "=?",
new String[]{filepath},
null, null, null);
if (cursor.moveToNext()) {
blob = cursor.getBlob(2);
if (blob != null) {
picture = BitmapFactory.decodeByteArray(blob, 0, blob.length);
}
//game = new Game(mContext, new File(filepath), cursor.getString(0), picture);
}
return null;
}
public void updateGame(String filepath, gameColumn col,
Object object) {
ContentValues values = new ContentValues();
switch (col) {
case GAME_PICTURE:
Bitmap picture = (Bitmap) object;
ByteArrayOutputStream out = new ByteArrayOutputStream();
picture.compress(Bitmap.CompressFormat.PNG, 100, out);
values.put(GAME_PICTURE, out.toByteArray());
break;
default:
return;
}
mDb.update(GAME_TABLE_NAME, values, GAME_FILE_PATH + "=?", new String[]{filepath});
}
public synchronized void removeGame(String filepath) {
mDb.delete(GAME_TABLE_NAME, GAME_FILE_PATH + "=?", new String[]{filepath});
}
public enum gameColumn {
GAME_TABLE_NAME, GAME_OPPONENT_ID, GAME_FILE_PATH,
GAME_PICTURE, GAME_DATE
}
//__________________________________________________________________________________________//
//--------------------------------------------------------------------------------------------------
private class DatabaseHelper extends SQLiteOpenHelper {
public DatabaseHelper(Context context) {
super(context, DB_NAME, null, DB_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
String createGameTableQuery = " CREATE TABLE IF NOT EXISTS "
+ GAME_TABLE_NAME + " ("
+ GAME_ID + " INTEGER, "
+ GAME_OPPONENT_ID + " VARCHAR(20), "
+ GAME_TRACK + " VARCHAR(30), "
+ GAME_FILE_PATH + " VARCHAR(50), "
+ GAME_PICTURE + " BLOB, "
+ GAME_GUESSES + " VARCHAR, "
+ GAME_DATE + " VARCHAR(50)"
+ ");";
//create game table
db.execSQL(createGameTableQuery);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
//TODO
}
}
}
答案 1 :(得分：0)
创建数据库对象：
public class Database extends SQLiteOpenHelper {
private static final String DATABASE_NAME = "Exampe.db";
private static final int DATABASE_VERSION = 1;
public static final String ID = "_id";
public static final String NAME = "name";
public static final String UUID = "uuid";
public static final String TABLE_NAME = "Example Something";
private static final String DATABASE_CREATE = "create table "
+ TABLE_NAME + "( " + ID
+ " integer primary key autoincrement, " + NAME
+ " text not null, " + UUID
+ " text not null);";
public Database(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL(DATABASE_CREATE);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
Log.w(Database.class.getName(), "Upgrading database from version " + oldVersion + "to " + newVersion + ", which will destroy all old data");
db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
}
}
现在你称之为
private SQLiteDatabase database;
private Database dbHelper;
private String[] allColumns = { Database.ID, Database.NAME};
public String ExampleSaveName(String name) {
database = dbHelper.getReadableDatabase();
ContentValues values = new ContentValues();
values.put("name", name);
values.put("uuid", uuid);
long insertId = database.insert(Database.TABLE_NAME, null, values);
Cursor cursor = database.query(Database.TABLE_NAME, allColumns, Database.ID + " = " + insertId, null,null, null, null);
cursor.moveToFirst();
return cursorToName(cursor);
}
}
答案 2 :(得分：0)
通过从我的设备卸载应用程序解决了这个问题。