我有一个关于在 android 项目中使用 SQLite 数据库的问题。我在资产文件夹中添加了我的数据库。我尝试访问数据库上的任何表，但应用程序在我的 HTC Desire S 设备“android.database.sqlite.SQLiteException：没有这样的表：”时出现错误。你能给我任何建议吗？
我的代码：
public static final String TABLE_NAME = "Airports";
public static final String COLUMN_ID = "_id";
public static final String COLUMN_CODE = "Code";
public static final String COLUMN_NAME = "Name";
public static final String COLUMN_NAMEFORSEARCH = "NameForSearch";
public static final String COLUMN_SEQUENCE = "OrderIndex";
private static String DB_PATH = "/data/data/com.pordiva.cepyol.activities/databases/";
private static String DB_NAME = "cepyol.db";
private SQLiteDatabase myDataBase;
private final Context myContext;
/**
* Constructor Takes and keeps a reference of the passed context in order to
* access to the application assets and resources.
*
* @param context
*/
private static final String DATABASE_NAME = "cepyol";
private static final int DATABASE_VERSION = 2;
public FlightSQLiteHelper(Context context) {
super(context, DB_NAME, null, 1);
this.myContext = context;
}
/**
* Creates a empty database on the system and rewrites it with your own
* database.
* */
public void createDataBase() throws IOException {
boolean dbExist = checkDataBase();
myDataBase = null;
if (dbExist) {
// do nothing - database already exist
} else {
// By calling this method and empty database will be created into
// the default system path
myDataBase = this.getReadableDatabase();
myDataBase.close();
// of your application so we are gonna be able to overwrite that
// database with our database.
try {
copyDataBase();
} catch (IOException e) {
throw new Error("Error copying database");
}
}
}
/**
* Check if the database already exist to avoid re-copying the file each
* time you open the application.
*
* @return true if it exists, false if it doesn't
*/
private boolean checkDataBase() {
SQLiteDatabase checkDB = null;
try {
String myPath = DB_PATH + DB_NAME;
checkDB = SQLiteDatabase.openDatabase(myPath, null,
SQLiteDatabase.OPEN_READWRITE);
} catch (SQLiteException e) {
// database does't exist yet.
}
if (checkDB != null) {
checkDB.close();
}
return checkDB != null ? true : false;
}
/**
* Copies your database from your local assets-folder to the just created
* empty database in the system folder, from where it can be accessed and
* handled. This is done by transfering bytestream.
* */
private void copyDataBase() throws IOException {
// Open your local db as the input stream
InputStream myInput = myContext.getAssets().open(DB_NAME);
// Path to the just created empty db
String outFileName = DB_PATH + DB_NAME;
// Open the empty db as the output stream
OutputStream myOutput = new FileOutputStream(outFileName);
// transfer bytes from the inputfile to the outputfile
byte[] buffer = new byte[1024];
int length;
while ((length = myInput.read(buffer)) > 0) {
myOutput.write(buffer, 0, length);
}
// Close the streams
myOutput.flush();
myOutput.close();
myInput.close();
}
public void openDataBase() throws SQLException {
// Open the database
String myPath = DB_PATH + DB_NAME;
myDataBase = SQLiteDatabase.openDatabase(myPath, null,
SQLiteDatabase.OPEN_READWRITE);
}
@Override
public synchronized void close() {
if (myDataBase != null)
myDataBase.close();
super.close();
}
@Override
public void onCreate(SQLiteDatabase myDataBase) {
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
}
public static String getDatabaseName() {
return DATABASE_NAME;
}
public static int getDatabaseVersion() {
return DATABASE_VERSION;
}
在那里打电话：
private int[] checkDB() {
FlightSQLiteHelper myDbHelper = new FlightSQLiteHelper(this);
int[] value = null;
try {
myDbHelper.createDataBase();
} catch (IOException ioe) {
throw new Error("Unable to create database");
}
try {
myDbHelper.openDataBase();
SQLiteDatabase db = myDbHelper.getWritableDatabase();
Cursor c = db.query("Airports", new String[] { "_id" }, null, null,
null, null, null);
startManagingCursor(c);
if (c != null) {
c.moveToFirst();
int index = 0;
while (c.moveToNext()) {
value[index] = c.getInt(index);
index++;
}
}
myDbHelper.close();
} catch (SQLException sqle) {
throw sqle;
}
return value;
}