我在应用程序中创建了数据库，代码提供了错误语法（代码1）表异常。我几乎阅读了关于这个例外的所有问题，做了所有的说法。但它仍然没有用。我无法找到问题所在。有没有人可以帮助我？
我的代码在这里：
public class NotesDatabaseAdapter {
public static final String KEY_NAME = "name";
public static final String KEY_IMAGE = "icon";
public static final String KEY_DATE_TIME = "when";
public static final String KEY_ROWID = "_id";
private static final String TAG = "NotesDatabaseAdapter";
private DatabaseHelper mDbHelper;
private SQLiteDatabase mDatabase;
private static final String DATABASE_TABLE = "downloads";
/**
* Khởi tạo Cơ sở dữ liệu
*/
private static final String DATABASE_NAME = "blogradio.db";
private static final int DATABASE_VERSION = 1;
private static final String CREATE_DOWNLOAD_TABLE = "create table "
+ DATABASE_TABLE + "(" + KEY_ROWID
+ " INTEGER PRIMARY KEY AUTOINCREMENT, " + KEY_NAME
+ " TEXT NOT NULL, " + KEY_IMAGE + " TEXT NOT NULL, "
+ KEY_DATE_TIME + " TEXT NOT NULL);";
private final Context mCtx;
private static class DatabaseHelper extends SQLiteOpenHelper {
DatabaseHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
Log.i("", "abc " + CREATE_DOWNLOAD_TABLE);
db.execSQL(CREATE_DOWNLOAD_TABLE);
}
@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 " + DATABASE_TABLE);
onCreate(db);
}
}
/**
* Constructor - takes the context to allow the database to be
* opened/created
*
* @param ctx
* the Context within which to work
*/
public NotesDatabaseAdapter(Context ctx) {
this.mCtx = ctx;
}
/**
* Open the notes database. If it cannot be opened, try to create a new
* instance of the database. If it cannot be created, throw an exception to
* signal the failure
*
* @return this (self reference, allowing this to be chained in an
* initialization call)
* @throws SQLException
* if the database could be neither opened or created
*/
public NotesDatabaseAdapter open() throws SQLException {
mDbHelper = new DatabaseHelper(mCtx);
mDatabase = mDbHelper.getWritableDatabase();
return this;
}
public void close() {
mDbHelper.close();
}
/**
* Create a new note using the title and body provided. If the note is
* successfully created return the new rowId for that note, otherwise return
* a -1 to indicate failure.
*
* @param title
* the title of the note
* @param body
* the body of the note
* @return rowId or -1 if failed
*/
public long createNote(ItemDownload item) {
ContentValues initialValues = new ContentValues();
initialValues.put(KEY_NAME, item.getName());
initialValues.put(KEY_IMAGE, item.getIcon());
initialValues.put(KEY_DATE_TIME, item.getWhen());
return mDatabase.insert(DATABASE_TABLE, null, initialValues);
}
/**
* Delete the note with the given rowId
*
* @param rowId
* id of note to delete
* @return true if deleted, false otherwise
*/
public boolean deleteNote(long rowId) {
return mDatabase.delete(DATABASE_TABLE, KEY_ROWID + "=" + rowId, null) > 0;
}
/**
* Return a Cursor over the list of all notes in the database
*
* @return Cursor over all notes
*/
// Lây toàn bộ các Ghi Chú để hiển thị lên Listview
public Cursor fetchAllNotes() {
return mDatabase.query(DATABASE_TABLE, new String[] { KEY_ROWID,
KEY_NAME, KEY_IMAGE, KEY_DATE_TIME }, null, null, null, null,
null);
}
/**
* Return a Cursor positioned at the note that matches the given rowId
*
* @param rowId
* id of note to retrieve
* @return Cursor positioned to matching note, if found
* @throws SQLException
* if note could not be found/retrieved
*/
public Cursor fetchNote(long rowId) throws SQLException {
Cursor mCursor =
mDatabase.query(true, DATABASE_TABLE, new String[] { KEY_ROWID,
KEY_NAME, KEY_IMAGE, KEY_DATE_TIME }, KEY_ROWID + "=" + rowId,
null, null, null, null, null);
if (mCursor != null) {
mCursor.moveToFirst();
}
return mCursor;
}
/**
* Update the note using the details provided. The note to be updated is
* specified using the rowId, and it is altered to use the title and body
* values passed in
*
* @param rowId
* id of note to update
* @param title
* value to set note title to
* @param body
* value to set note body to
* @return true if the note was successfully updated, false otherwise
*/
public boolean updateNote(long rowId, ItemDownload item) {
ContentValues args = new ContentValues();
args.put(KEY_NAME, item.getName());
args.put(KEY_IMAGE, item.getIcon());
args.put(KEY_DATE_TIME, item.getWhen());
return mDatabase.update(DATABASE_TABLE, args, KEY_ROWID + "=" + rowId,
null) > 0;
}
}
MainActivity：
public class RequestClass extends Activity implements OnClickListener {
Button start, stop, startActivity;
int btnStart, btnStop;
public static final String STATE = "start";
private Intent intent;
NotesDatabaseAdapter db;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.request_layout);
db = new NotesDatabaseAdapter(RequestClass.this);
db.open();
start = (Button) findViewById(R.id.btnStartService);
stop = (Button) findViewById(R.id.btnStopService);
startActivity = (Button) findViewById(R.id.btnStartActivity);
start.setOnClickListener(this);
stop.setOnClickListener(this);
startActivity.setOnClickListener(this);
}
@Override
public void onClick(View view) {
switch (view.getId()) {
case R.id.btnStartService:
intent = new Intent(this, ServiceClass.class);
intent.putExtra(STATE, "http://media3.nhacvietplus.com.vn/Upload/CMS/Nam_2015/Thang_5/Ngay_7/Images/blog-radio389-5.jpg");
// ItemDownload item = new ItemDownload("BLOGRADIO", "xxx", "http://media3.nhacvietplus.com.vn/Upload/CMS/Nam_2015/Thang_5/Ngay_7/Images/blog-radio389-5.jpg");
// db.createNote(item);
// db.close();
startService(intent);
break;
case R.id.btnStopService:
stopService(intent);
break;
case R.id.btnStartActivity:
Intent i = new Intent(RequestClass.this, ResponseClass.class);
startActivity(i);
break;
}
}
@Override
protected void onResume() {
super.onResume();
}
@Override
protected void onPause() {
super.onPause();
}
@Override
protected void onDestroy() {
super.onDestroy();
}
}
Logcat：
05-14 14:08:41.152: E/SQLiteLog(1979): (1) near "when": syntax error
05-14 14:08:41.152: D/AndroidRuntime(1979): Shutting down VM
05-14 14:08:41.152: W/dalvikvm(1979): threadid=1: thread exiting with uncaught exception (group=0xa61fe908)
05-14 14:08:41.156: E/AndroidRuntime(1979): FATAL EXCEPTION: main
05-14 14:08:41.156: E/AndroidRuntime(1979): java.lang.RuntimeException: Unable to start activity ComponentInfo{android.tadev.demodownloadservice/android.tadev.downloadservice.temp.RequestClass}: android.database.sqlite.SQLiteException: near "when": syntax error (code 1): , while compiling: create table downloads(_id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, icon TEXT NOT NULL, when TEXT NOT NULL);
05-14 14:08:41.156: E/AndroidRuntime(1979): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2180)
05-14 14:08:41.156: E/AndroidRuntime(1979): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
05-14 14:08:41.156: E/AndroidRuntime(1979): at android.app.ActivityThread.access$600(ActivityThread.java:141)
05-14 14:08:41.156: E/AndroidRuntime(1979): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
05-14 14:08:41.156: E/AndroidRuntime(1979): at android.os.Handler.dispatchMessage(Handler.java:99)
05-14 14:08:41.156: E/AndroidRuntime(1979): at android.os.Looper.loop(Looper.java:137)
05-14 14:08:41.156: E/AndroidRuntime(1979): at android.app.ActivityThread.main(ActivityThread.java:5041)
05-14 14:08:41.156: E/AndroidRuntime(1979): at java.lang.reflect.Method.invokeNative(Native Method)
05-14 14:08:41.156: E/AndroidRuntime(1979): at java.lang.reflect.Method.invoke(Method.java:511)
05-14 14:08:41.156: E/AndroidRuntime(1979): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
05-14 14:08:41.156: E/AndroidRuntime(1979): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
05-14 14:08:41.156: E/AndroidRuntime(1979): at dalvik.system.NativeStart.main(Native Method)
05-14 14:08:41.156: E/AndroidRuntime(1979): Caused by: android.database.sqlite.SQLiteException: near "when": syntax error (code 1): , while compiling: create table downloads(_id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT NOT NULL, icon TEXT NOT NULL, when TEXT NOT NULL);
05-14 14:08:41.156: E/AndroidRuntime(1979): at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method)
05-14 14:08:41.156: E/AndroidRuntime(1979): at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:882)
05-14 14:08:41.156: E/AndroidRuntime(1979): at android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:493)
05-14 14:08:41.156: E/AndroidRuntime(1979): at android.database.sqlite.SQLiteSession.prepare(SQLiteSession.java:588)
05-14 14:08:41.156: E/AndroidRuntime(1979): at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:58)
05-14 14:08:41.156: E/AndroidRuntime(1979): at android.database.sqlite.SQLiteStatement.<init>(SQLiteStatement.java:31)
05-14 14:08:41.156: E/AndroidRuntime(1979): at android.database.sqlite.SQLiteDatabase.executeSql(SQLiteDatabase.java:1663)
05-14 14:08:41.156: E/AndroidRuntime(1979): at android.database.sqlite.SQLiteDatabase.execSQL(SQLiteDatabase.java:1594)
05-14 14:08:41.156: E/AndroidRuntime(1979): at android.tadev.downloadservice.temp.NotesDatabaseAdapter$DatabaseHelper.onCreate(NotesDatabaseAdapter.java:44)
05-14 14:08:41.156: E/AndroidRuntime(1979): at android.database.sqlite.SQLiteOpenHelper.getDatabaseLocked(SQLiteOpenHelper.java:252)
05-14 14:08:41.156: E/AndroidRuntime(1979): at android.database.sqlite.SQLiteOpenHelper.getWritableDatabase(SQLiteOpenHelper.java:164)
05-14 14:08:41.156: E/AndroidRuntime(1979): at android.tadev.downloadservice.temp.NotesDatabaseAdapter.open(NotesDatabaseAdapter.java:79)
05-14 14:08:41.156: E/AndroidRuntime(1979): at android.tadev.downloadservice.temp.RequestClass.onCreate(RequestClass.java:23)
05-14 14:08:41.156: E/AndroidRuntime(1979): at android.app.Activity.performCreate(Activity.java:5104)
05-14 14:08:41.156: E/AndroidRuntime(1979): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
05-14 14:08:41.156: E/AndroidRuntime(1979): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
05-14 14:08:41.156: E/AndroidRuntime(1979): ... 11 more
答案 0 :(得分：1)
您无法调用“WHEN”列，因为它是sqlite
中的关键字答案 1 :(得分：1)
'when'是一个sqlite关键字。
public static final String KEY_DATE_TIME = "when";
像这样改变： -
public static final String KEY_DATE_TIME = "date_and_time";