Android 如何添加新的表列？
这是我的Android项目。我尝试创建一个新的表列：KEY\u示例。但它不起作用。我将把我的代码放在下面，我想解决这个问题。有人能帮我吗？这很重要。我是个新手。关键的例子不起作用。这是我的代码，也是我要做的 JavaAndroid 如何添加新的表列？,android,android-sqlite,Android,Android Sqlite,这是我的Android项目。我尝试创建一个新的表列：KEY\u示例。但它不起作用。我将把我的代码放在下面，我想解决这个问题。有人能帮我吗？这很重要。我是个新手。关键的例子不起作用。这是我的代码，也是我要做的 Java public class DictionaryDatabase { private static final String TAG = "DictionaryDatabase"; public static final String KEY_WORD = SearchManage
public class DictionaryDatabase {
private static final String TAG = "DictionaryDatabase";
public static final String KEY_WORD = SearchManager.SUGGEST_COLUMN_TEXT_1;
public static final String KEY_DEFINITION = SearchManager.SUGGEST_COLUMN_TEXT_2;
public static final String KEY_EXAMPLE = SearchManager.SUGGEST_COLUMN_INTENT_EXTRA_DATA;
private static final String DATABASE_NAME = "dictionary";
private static final String FTS_VIRTUAL_TABLE = "FTSdictionary";
private static final int DATABASE_VERSION = 3;
private final DictionaryOpenHelper mDatabaseOpenHelper;
private static final HashMap<String,String> mColumnMap = buildColumnMap();
public DictionaryDatabase(Context context) {
mDatabaseOpenHelper = new DictionaryOpenHelper(context);
}
private static HashMap<String,String> buildColumnMap() {
HashMap<String,String> map = new HashMap<String,String>();
map.put(KEY_WORD, KEY_WORD);
map.put(KEY_DEFINITION, KEY_DEFINITION);
map.put(KEY_EXAMPLE, KEY_EXAMPLE);
map.put(BaseColumns._ID, "rowid AS " +
BaseColumns._ID);
map.put(SearchManager.SUGGEST_COLUMN_INTENT_DATA_ID, "rowid AS " +
SearchManager.SUGGEST_COLUMN_INTENT_DATA_ID);
map.put(SearchManager.SUGGEST_COLUMN_SHORTCUT_ID, "rowid AS " +
SearchManager.SUGGEST_COLUMN_SHORTCUT_ID);
return map;
}
public Cursor getWord(String rowId, String[] columns) {
String selection = "rowid = ?";
String[] selectionArgs = new String[] {rowId};
return query(selection, selectionArgs, columns);
}
public Cursor getWordMatches(String query, String[] columns) {
String selection = KEY_WORD + " MATCH ?";
String[] selectionArgs = new String[] {query+"*"};
return query(selection, selectionArgs, columns);
}
private Cursor query(String selection, String[] selectionArgs, String[] columns) {
SQLiteQueryBuilder builder = new SQLiteQueryBuilder();
builder.setTables(FTS_VIRTUAL_TABLE);
builder.setProjectionMap(mColumnMap);
Cursor cursor = builder.query(mDatabaseOpenHelper.getReadableDatabase(),
columns, selection, selectionArgs, null, null, null);
if (cursor == null) {
return null;
} else if (!cursor.moveToFirst()) {
cursor.close();
return null;
}
return cursor;
}
private static class DictionaryOpenHelper extends SQLiteOpenHelper {
private final Context mHelperContext;
private SQLiteDatabase mDatabase;
private static final String FTS_TABLE_CREATE =
"CREATE VIRTUAL TABLE " + FTS_VIRTUAL_TABLE +
" USING fts3 (" +
KEY_WORD + ", " +
KEY_DEFINITION +
KEY_EXAMPLE + ");";
DictionaryOpenHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
mHelperContext = context;
}
@Override
public void onCreate(SQLiteDatabase db) {
mDatabase = db;
mDatabase.execSQL(FTS_TABLE_CREATE);
loadDictionary();
}
private void loadDictionary() {
new Thread(new Runnable() {
public void run() {
try {
loadWords();
} catch (IOException e) {
throw new RuntimeException(e);
}
}
}).start();
}
private void loadWords() throws IOException {
Log.d(TAG, "Loading words...");
final Resources resources = mHelperContext.getResources();
InputStream inputStream = resources.openRawResource(R.raw.definitions);
BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream));
try {
String line;
while ((line = reader.readLine()) != null) {
String[] strings = TextUtils.split(line, "-");
if (strings.length < 2) continue;
long id = addWord(strings[0].trim(), strings[1].trim(), strings[2].trim());
if (id < 0) {
Log.e(TAG, "unable to add word: " + strings[0].trim());
}
}
} finally {
reader.close();
}
Log.d(TAG, "DONE loading words.");
}
public long addWord(String word, String definition, String example) {
ContentValues initialValues = new ContentValues();
initialValues.put(KEY_WORD, word);
initialValues.put(KEY_DEFINITION, definition);
initialValues.put(KEY_EXAMPLE, example);
return mDatabase.insert(FTS_VIRTUAL_TABLE, null, initialValues);
}
@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 " + FTS_VIRTUAL_TABLE);
onCreate(db);
}
}
}
我很想帮助你，但是有一些问题 第一：你一小时前才发布了这个问题。一般来说，stackoverflow社区并不急于等待下一个问题的出现。你得有耐心 第二：你只发布了你的程序。也许有人愿意一步一步地解决这个问题，我希望他或她好运，但我还是犹豫着去做。stackoverflow不是我的全职工作，所以我不能花15-20分钟来搞清楚你的程序做了什么（如果有的话）。 这不是一个简单的程序。您有一个数据库、一个内容提供商和两个活动 第三：你的程序没有一条评论。使调试变得更加困难 第四：你说“我试图创建一个新的表列：KEY_EXAMPLE。但它不起作用。”会发生什么？为什么你认为它不起作用？你期望它做什么 stackoverflow在您遇到某个特定问题或难题时“起作用”。本质上，当你问“为我修改我的程序”时，效果最差 说到这里，我要大胆地猜测一下：你以前运行过这个应用程序并创建了数据库的早期版本吗？如果是这样，我看不到任何地方您正在删除以前的版本。在删除旧版本之前，您将无法创建新版本，包括新列。您可以在设置>应用程序>应用程序名>清除数据中执行此操作，也可以将其放入程序本身
祝你好运 没人能帮我？？？
public class DictionaryProvider extends ContentProvider {
String TAG = "DictionaryProvider";
public static String AUTHORITY = "com.pesquisa.dicionario.searchabledict.DictionaryProvider";
public static final Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY + "/dictionary");
public static final String WORDS_MIME_TYPE = ContentResolver.CURSOR_DIR_BASE_TYPE +
"/vnd.pesquisa.dicionario.searchabledict";
public static final String DEFINITION_MIME_TYPE = ContentResolver.CURSOR_ITEM_BASE_TYPE +
"/vnd.pesquisa.dicionario.searchabledict";
private DictionaryDatabase mDictionary;
private static final int SEARCH_WORDS = 0;
private static final int GET_WORD = 1;
private static final int SEARCH_SUGGEST = 2;
private static final int REFRESH_SHORTCUT = 3;
private static final UriMatcher sURIMatcher = buildUriMatcher();
private static UriMatcher buildUriMatcher() {
UriMatcher matcher = new UriMatcher(UriMatcher.NO_MATCH);
matcher.addURI(AUTHORITY, "dictionary", SEARCH_WORDS);
matcher.addURI(AUTHORITY, "dictionary/#", GET_WORD);
matcher.addURI(AUTHORITY, SearchManager.SUGGEST_URI_PATH_QUERY, SEARCH_SUGGEST);
matcher.addURI(AUTHORITY, SearchManager.SUGGEST_URI_PATH_QUERY + "/*", SEARCH_SUGGEST);
matcher.addURI(AUTHORITY, SearchManager.SUGGEST_URI_PATH_SHORTCUT, REFRESH_SHORTCUT);
matcher.addURI(AUTHORITY, SearchManager.SUGGEST_URI_PATH_SHORTCUT + "/*", REFRESH_SHORTCUT);
return matcher;
}
@Override
public boolean onCreate() {
mDictionary = new DictionaryDatabase(getContext());
return true;
}
@Override
public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs,
String sortOrder) {
switch (sURIMatcher.match(uri)) {
case SEARCH_SUGGEST:
if (selectionArgs == null) {
throw new IllegalArgumentException(
"selectionArgs must be provided for the Uri: " + uri);
}
return getSuggestions(selectionArgs[0]);
case SEARCH_WORDS:
if (selectionArgs == null) {
throw new IllegalArgumentException(
"selectionArgs must be provided for the Uri: " + uri);
}
return search(selectionArgs[0]);
case GET_WORD:
return getWord(uri);
case REFRESH_SHORTCUT:
return refreshShortcut(uri);
default:
throw new IllegalArgumentException("Unknown Uri: " + uri);
}
}
private Cursor getSuggestions(String query) {
query = query.toLowerCase();
String[] columns = new String[] {
BaseColumns._ID,
DictionaryDatabase.KEY_WORD,
SearchManager.SUGGEST_COLUMN_INTENT_DATA_ID};
return mDictionary.getWordMatches(query, columns);
}
private Cursor search(String query) {
query = query.toLowerCase();
String[] columns = new String[] {
BaseColumns._ID,
DictionaryDatabase.KEY_WORD,
DictionaryDatabase.KEY_DEFINITION,
DictionaryDatabase.KEY_EXAMPLE};
return mDictionary.getWordMatches(query, columns);
}
private Cursor getWord(Uri uri) {
String rowId = uri.getLastPathSegment();
String[] columns = new String[] {
DictionaryDatabase.KEY_WORD,
DictionaryDatabase.KEY_DEFINITION,
DictionaryDatabase.KEY_EXAMPLE};
return mDictionary.getWord(rowId, columns);
}
private Cursor refreshShortcut(Uri uri) {
String rowId = uri.getLastPathSegment();
String[] columns = new String[] {
BaseColumns._ID,
DictionaryDatabase.KEY_WORD,
DictionaryDatabase.KEY_DEFINITION,
DictionaryDatabase.KEY_EXAMPLE,
SearchManager.SUGGEST_COLUMN_SHORTCUT_ID,
SearchManager.SUGGEST_COLUMN_INTENT_DATA_ID};
return mDictionary.getWord(rowId, columns);
}
@Override
public String getType(Uri uri) {
switch (sURIMatcher.match(uri)) {
case SEARCH_WORDS:
return WORDS_MIME_TYPE;
case GET_WORD:
return DEFINITION_MIME_TYPE;
case SEARCH_SUGGEST:
return SearchManager.SUGGEST_MIME_TYPE;
case REFRESH_SHORTCUT:
return SearchManager.SHORTCUT_MIME_TYPE;
default:
throw new IllegalArgumentException("Unknown URL " + uri);
}
}
@Override
public Uri insert(Uri uri, ContentValues values) {
throw new UnsupportedOperationException();
}
@Override
public int delete(Uri uri, String selection, String[] selectionArgs) {
throw new UnsupportedOperationException();
}
@Override
public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
throw new UnsupportedOperationException();
}
}
public class SenseDictionary extends Activity {
private TextView mTextView;
private ListView mListView;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.main);
mTextView = (TextView) findViewById(R.id.text);
mListView = (ListView) findViewById(R.id.list);
handleIntent(getIntent());
}
@Override
protected void onNewIntent(Intent intent) {
handleIntent(intent);
}
private void handleIntent(Intent intent) {
if (Intent.ACTION_VIEW.equals(intent.getAction())) {
Intent wordIntent = new Intent(this, WordActivity.class);
wordIntent.setData(intent.getData());
startActivity(wordIntent);
} else if (Intent.ACTION_SEARCH.equals(intent.getAction())) {
String query = intent.getStringExtra(SearchManager.QUERY);
showResults(query);
}
}
private void showResults(String query) {
Cursor cursor = managedQuery(DictionaryProvider.CONTENT_URI, null, null,
new String[] {query}, null);
if (cursor == null) {
mTextView.setText(getString(R.string.no_results, new Object[] {query}));
} else {
int count = cursor.getCount();
String countString = getResources().getQuantityString(R.plurals.search_results,
count, new Object[] {count, query});
mTextView.setText(countString);
String[] from = new String[] { DictionaryDatabase.KEY_WORD,
DictionaryDatabase.KEY_DEFINITION,
DictionaryDatabase.KEY_EXAMPLE};
int[] to = new int[] { R.id.word,
R.id.definition,
R.id.example};
SimpleCursorAdapter words = new SimpleCursorAdapter(this,
R.layout.result, cursor, from, to);
mListView.setAdapter(words);
mListView.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Intent wordIntent = new Intent(getApplicationContext(), WordActivity.class);
Uri data = Uri.withAppendedPath(DictionaryProvider.CONTENT_URI,
String.valueOf(id));
wordIntent.setData(data);
startActivity(wordIntent);
}
});
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.main, menu);
if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB){
SearchManager searchManager = (SearchManager) getSystemService(Context.SEARCH_SERVICE);
SearchView searchView = (SearchView) menu.findItem(R.id.search).getActionView();
searchView.setSearchableInfo(searchManager.getSearchableInfo(getComponentName()));
searchView.setIconifiedByDefault(false);
}
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.search:
onSearchRequested();
return true;
default:
return false;
}
}
}
public class WordActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.word);
if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB){
ActionBar actionBar = getActionBar();
actionBar.setDisplayHomeAsUpEnabled(true);
}
Uri uri = getIntent().getData();
Cursor cursor = managedQuery(uri, null, null, null, null);
if (cursor == null) {
finish();
} else {
cursor.moveToFirst();
TextView word = (TextView) findViewById(R.id.word);
TextView definition = (TextView) findViewById(R.id.definition);
TextView example = (TextView) findViewById(R.id.example);
int wIndex = cursor.getColumnIndexOrThrow(DictionaryDatabase.KEY_WORD);
int dIndex = cursor.getColumnIndexOrThrow(DictionaryDatabase.KEY_DEFINITION);
int eIndex = cursor.getColumnIndexOrThrow(DictionaryDatabase.KEY_EXAMPLE);
word.setText(cursor.getString(wIndex));
definition.setText(cursor.getString(dIndex));
example.setText(cursor.getString(eIndex));
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.main, menu);
if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB){
SearchManager searchManager = (SearchManager) getSystemService(Context.SEARCH_SERVICE);
SearchView searchView = (SearchView) menu.findItem(R.id.search).getActionView();
searchView.setSearchableInfo(searchManager.getSearchableInfo(getComponentName()));
searchView.setIconifiedByDefault(false);
}
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.search:
onSearchRequested();
return true;
case android.R.id.home:
Intent intent = new Intent(this, SenseDictionary.class);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(intent);
return true;
default:
return false;
}
}
}