Hi all, I make a content provider named 'DictionaryProvider' (Based on NotepadProvider). When my program run to command 'qb.query(db, projection, selection, selectionArgs, null, null, orderBy);', error happen. I don't know how to fix. please help me. Below is my code // file main calling DictionnaryProvider @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.dictionary); final String[] PROJECTION = new String[] { DicColumns._ID, // 0 DicColumns.KEY_WORD, // 1 DicColumns.KEY_DEFINITION // 2 }; Cursor c = managedQuery(DicColumns.CONTENT_URI, PROJECTION, null, null, DicColumns.DEFAULT_SORT_ORDER); String str = ""; if (c.moveToFirst()) { int wordColumn = c.getColumnIndex("KEY_WORD"); int defColumn = c.getColumnIndex("KEY_DEFINITION"); do { // Get the field values str = ""; str += c.getString(wordColumn); str +="\n"; str +=c.getString(defColumn); } while (c.moveToNext()); } Toast.makeText(this, str, Toast.LENGTH_SHORT).show(); } // file DictionaryProvider.java package com.example.helloandroid; import java.util.HashMap; import android.content.ContentProvider; import android.content.ContentValues; import android.content.UriMatcher; import android.database.Cursor; import android.database.sqlite.SQLiteDatabase; import android.database.sqlite.SQLiteQueryBuilder; import android.net.Uri; import android.text.TextUtils; import com.example.helloandroid.Dictionary.DicColumns; public class DictionaryProvider extends ContentProvider { //private static final String TAG = "DictionaryProvider"; private DictionaryOpenHelper dbdic; static final int DATABASE_VERSION = 1; static final String DICTIONARY_DATABASE_NAME = "dictionarydb"; static final String DICTIONARY_TABLE_NAME = "dictionary"; private static final UriMatcher sUriMatcher; private static HashMap<String, String> sDicProjectionMap; @Override public int delete(Uri arg0, String arg1, String[] arg2) { // TODO Auto-generated method stub return 0; } @Override public String getType(Uri arg0) { // TODO Auto-generated method stub return null; } @Override public Uri insert(Uri arg0, ContentValues arg1) { // TODO Auto-generated method stub return null; } @Override public boolean onCreate() { // TODO Auto-generated method stub dbdic = new DictionaryOpenHelper(getContext(), DICTIONARY_DATABASE_NAME, null, DATABASE_VERSION); return true; } @Override public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) { SQLiteQueryBuilder qb = new SQLiteQueryBuilder(); qb.setTables(DICTIONARY_TABLE_NAME); switch (sUriMatcher.match(uri)) { case 1: qb.setProjectionMap(sDicProjectionMap); break; case 2: qb.setProjectionMap(sDicProjectionMap); qb.appendWhere(DicColumns._ID + "=" + uri.getPathSegments().get(1)); break; default: throw new IllegalArgumentException("Unknown URI " + uri); } // If no sort order is specified use the default String orderBy; if (TextUtils.isEmpty(sortOrder)) { orderBy = DicColumns.DEFAULT_SORT_ORDER; } else { orderBy = sortOrder; } // Get the database and run the query SQLiteDatabase db = dbdic.getReadableDatabase(); Cursor c = qb.query(db, projection, selection, selectionArgs, null, null, orderBy); // Tell the cursor what uri to watch, so it knows when its source data changes c.setNotificationUri(getContext().getContentResolver(), uri); return c; } @Override public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) { // TODO Auto-generated method stub return 0; } static { sUriMatcher = new UriMatcher(UriMatcher.NO_MATCH); sUriMatcher.addURI(Dictionary.AUTHORITY, "dictionary", 1); sUriMatcher.addURI(Dictionary.AUTHORITY, "dictionary/#", 2); sDicProjectionMap = new HashMap<String, String>(); sDicProjectionMap.put(DicColumns._ID, DicColumns._ID); sDicProjectionMap.put(DicColumns.KEY_WORD, DicColumns.KEY_WORD); sDicProjectionMap.put(DicColumns.KEY_DEFINITION, DicColumns.KEY_DEFINITION); // Support for Live Folders. /*sLiveFolderProjectionMap = new HashMap<String, String>(); sLiveFolderProjectionMap.put(LiveFolders._ID, NoteColumns._ID + " AS " + LiveFolders._ID); sLiveFolderProjectionMap.put(LiveFolders.NAME, NoteColumns.TITLE + " AS " + LiveFolders.NAME);*/ // Add more columns here for more robust Live Folders. } } // file Dictionary.java package com.example.helloandroid; import android.net.Uri; import android.provider.BaseColumns; /** * Convenience definitions for DictionaryProvider */ public final class Dictionary { public static final String AUTHORITY = "com.example.helloandroid.provider.Dictionary"; // This class cannot be instantiated private Dictionary() {} /** * Dictionary table */ public static final class DicColumns implements BaseColumns { // This class cannot be instantiated private DicColumns() {} /** * The content:// style URL for this table */ public static final Uri CONTENT_URI = Uri.parse("content://" + AUTHORITY + "/dictionary"); /** * The MIME type of {@link #CONTENT_URI} providing a directory of notes. */ //public static final String CONTENT_TYPE = "vnd.android.cursor.dir/vnd.google.note"; /** * The MIME type of a {@link #CONTENT_URI} sub-directory of a single note. */ //public static final String CONTENT_ITEM_TYPE = "vnd.android.cursor.item/vnd.google.note"; /** * The default sort order for this table */ public static final String DEFAULT_SORT_ORDER = "modified DESC"; /** * The key_word of the dictionary * <P>Type: TEXT</P> */ public static final String KEY_WORD = "KEY_WORD"; /** * The key_definition of word * <P>Type: TEXT</P> */ public static final String KEY_DEFINITION = "KEY_DEFINITION"; } } thanks so much