Android SQL在类似于记事本教程的应用上出现问题：CursorIndexOutOfBoundsException: Index 0 requests, with a size of 0

Question

我正在尝试使用 Android 的记事本教程作为指导来制作一个应用程序。我可以毫无问题地在表中插入新元素，但如果我想更新此元素之一的字段，则会提示错误。我多次重温该教程，但找不到解决方案。

谢谢你！

这是菜单（插入、删除和更新）

package citic.android.remoteir;

import android.app.ListActivity; 导入 android.content.Intent; 导入 android.database.Cursor; 导入 android.os.Bundle； 导入 android.view.ContextMenu; 导入 android.view.Menu； 导入 android.view.MenuItem; 导入 android.view.View； 导入 android.view.ContextMenu.ContextMenuInfo; 导入 android.widget.SimpleCursorAdapter; 导入 android.widget.AdapterView.AdapterContextMenuInfo;

public class ServerCp extends ListActivity{

private RemoteIrDbAdapter mDbHelper; 

private static final int ACTIVITY_CREATE=0;
private static final int ACTIVITY_EDIT=1;

private static final int  INSERT_ID = Menu.FIRST;
private static final int  EDIT_ID = Menu.FIRST + 1;
private static final int  DELETE_ID = Menu.FIRST + 2;

@Override
public void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);
    setContentView(R.layout.contentlist);

    mDbHelper = new RemoteIrDbAdapter(this);
    mDbHelper.open();

    fillDataServer();
    registerForContextMenu(getListView());

}

private void fillDataServer() {

    Cursor c = mDbHelper.fetchAllQueryDataAutoCompleteServerName();
    startManagingCursor(c);

    String[] from;

    from = new String[] { RemoteIrDbAdapter.KEY_NAMESERVER}; 

    int[] to = new int[] { R.id.row1 };

    SimpleCursorAdapter data =
        new SimpleCursorAdapter(this, R.layout.listrow, c, from, to);

    setListAdapter(data);
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    super.onCreateOptionsMenu(menu);
    menu.add(0, INSERT_ID, 0, R.string.menu_insert_server);
    return true;
}

@Override
public boolean onMenuItemSelected(int featureId, MenuItem item) {
    switch(item.getItemId()) {
    case INSERT_ID:
        createServer();
        return true;
    }

    return super.onMenuItemSelected(featureId, item);
}


public void onCreateContextMenu(ContextMenu menu, View v,
        ContextMenuInfo menuInfo) {
    super.onCreateContextMenu(menu, v, menuInfo);
    menu.add(0, EDIT_ID, 0, R.string.menu_edit_server);
    menu.add(0, DELETE_ID, 0, R.string.menu_delete_server);

}

@Override
public boolean onContextItemSelected(MenuItem item) {
    switch(item.getItemId()) {
    case EDIT_ID:
        AdapterContextMenuInfo infoEdit = (AdapterContextMenuInfo) item.getMenuInfo();
        Intent i = new Intent(this, ServerEdit.class);
        i.putExtra(RemoteIrDbAdapter.KEY_ROWIDSERVER, infoEdit.id);
        startActivityForResult(i, ACTIVITY_EDIT);

    case DELETE_ID:
        AdapterContextMenuInfo infoDelete = (AdapterContextMenuInfo) item.getMenuInfo();
        mDbHelper.deleteQueryDataServer(infoDelete.id);
        fillDataServer();
        return true;
    }
    return super.onContextItemSelected(item);
}

private void createServer() {
    Intent i = new Intent(this, ServerEdit.class);
    startActivityForResult(i, ACTIVITY_CREATE);
}

/*@Override
protected void onListItemClick(ListView l, View v, int position, long id) {
    super.onListItemClick(l, v, position, id);
    Intent i = new Intent(this, ProfileEdit.class);
    i.putExtra(RemoteIrDbAdapter.KEY_ROWID, id);
    startActivityForResult(i, ACTIVITY_EDIT);
}


*/
    @Override
    protected void onActivityResult(int requestCode, int resultCode, 
                                    Intent intent) {
        super.onActivityResult(requestCode, resultCode, intent);
        fillDataServer();
    }


}

这是编辑和创建类：

package citic.android.remoteir;

import android.app.Activity; 导入 android.database.Cursor; 导入 android.os.Bundle； 导入 android.view.View； 导入 android.widget.Button; 导入 android.widget.EditText;

public class ServerEdit extends Activity{

private EditText mNameText;
private EditText mIpText;
private EditText mPortText;
private Long mRowId;
private RemoteIrDbAdapter mDbHelper;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    mDbHelper = new RemoteIrDbAdapter(this);
    mDbHelper.open();
    setContentView(R.layout.editserver);


    mNameText = (EditText) findViewById(R.id.name);
    mIpText = (EditText) findViewById(R.id.ip);
    mPortText = (EditText) findViewById(R.id.port);

    Button confirmButton = (Button) findViewById(R.id.confirm);

    mRowId = savedInstanceState != null ? savedInstanceState.getLong(RemoteIrDbAdapter.KEY_ROWIDSERVER) 
                                        : null;
    if (mRowId == null) {
        Bundle extras = getIntent().getExtras();            
        mRowId = extras != null ? extras.getLong(RemoteIrDbAdapter.KEY_ROWIDSERVER) 
                                : null;
    }

    System.out.println("el rowid es" + mRowId);
    populateFields();

    confirmButton.setOnClickListener(new View.OnClickListener() {

        public void onClick(View view) {
            setResult(RESULT_OK);
            finish();
        }

    });
}

private void populateFields() {  // <- This is where the error refers
    if (mRowId != null) {
        Cursor server = mDbHelper.fetchServer(mRowId);
        startManagingCursor(server);
        mIpText.setText(server.getString(
                server.getColumnIndexOrThrow(RemoteIrDbAdapter.KEY_IP)));
        mPortText.setText(server.getString(
                server.getColumnIndexOrThrow(RemoteIrDbAdapter.KEY_PORT)));
        mNameText.setText(server.getString(
                server.getColumnIndexOrThrow(RemoteIrDbAdapter.KEY_NAMESERVER)));    
    }
}

@Override
protected void onSaveInstanceState(Bundle outState) {
    super.onSaveInstanceState(outState);
    outState.putLong(RemoteIrDbAdapter.KEY_ROWIDSERVER, mRowId);
}

@Override
protected void onPause() {
    super.onPause();
    saveState();
}

@Override
protected void onResume() {
    super.onResume();
    populateFields();
}

private void saveState() {
    String name = mNameText.getText().toString();
    String ip = mIpText.getText().toString();
    String port = mPortText.getText().toString();

    if (mRowId == null) {
        long id = mDbHelper.createQueryDataServer(ip, port, name);
        if (id > 0) {
            mRowId = id;
        }
    } else {
        mDbHelper.updateServerData(mRowId, ip, port, name);
    }
}

这里

是数据库管理：

package citic.android.remoteir;

import android.content.ContentValues; 导入 android.content.Context； 导入 android.database.Cursor; 导入 android.database.SQLException; 导入 android.database.sqlite.SQLiteDatabase; 导入 android.database.sqlite.SQLiteOpenHelper; 导入 android.util.Log；

public class RemoteIrDbAdapter{

    public static final boolean DISTINCT = true;

    public static final String KEY_ROWIDSERVER= "_id"; //ANTES _IDS
    public static final String KEY_PORT = "port";
    public static final String KEY_IP = "ip";
    public static final String KEY_NAMESERVER = "server";

    public static final String KEY_ROWIDPROFILE= "_id"; //ANTES _id
    public static final String KEY_NAMEPROFILE= "profile";

    //public static final String KEY_ROWID = "_id";

    private static final String TAG = "RemoteIrDbAdapterBak";
    private DatabaseHelper mDbHelper;
    private SQLiteDatabase mDb;


    private static final String DATABASE_CREATE_SERVER = "create table server (_id integer primary key autoincrement,ip string not null, port string not null, server string not null);";
            /*"create table server (_id integer primary key autoincrement, " 
                    + "ip string not null, port string not null, server string not null);";*/

    private static final String DATABASE_CREATE_PROFILE = "create table profile (_id integer primary key autoincrement, profile string not null);";

            /*"create table profile (_id integer primary key autoincrement, "
                    + "profile string not null);";*/

    private static final String DATABASE_CREATE_SERPRO = "create table serpro (_ids integer not null, _idp integer not null, PRIMARY KEY (_ids, _idp), CONSTRAINT fk_idsps FOREIGN KEY (_ids) REFERENCES server(_id) ON DELETE CASCADE, CONSTRAINT fk_idspp FOREIGN KEY (_ids) REFERENCES server(_id) ON DELETE CASCADE);";

            /*"create table serpro (_ids integer not null, _idp integer not null, PRIMARY KEY (_ids, _idp), " 
                    + " CONSTRAINT fk_idsps REFERENCES server(_id) ON DELETE CASCADE "
                    + " CONSTRAINT fk_idspp REFERENCES profile(_id) ON DELETE CASCADE);";*/

private static final String DATABASE_TABLE_SERVER = "server";

    private static final String DATABASE_TABLE_PROFILE = "profile";

    private static final String DATABASE_TABLE_SERPRO = "serpro";

    private static final String TRIGGER_SERPRO_IP = "create trigger serpro_pi before insert on serpro for each row when ((select _id from profile where _id = new._id) is null) begin select raise(abort, 'insert on table \"serpro\" violates foreign key constraint \"fk_idspp\"'); end;";
    /*"CREATE TRIGGER SERPRO_PI BEFORE INSERT ON serpro FOR EACH ROW BEGIN SELECT CASE WHEN ((SELECT _id FROM profile WHERE _id = NEW._id) IS NULL ) THEN RAISE (ABORT, ‘insert on table serpro violates foreign key constraint fk_idspp’) END; END;";*/

    private static final String TRIGGER_SERPRO_UP = "create trigger serpro_up before update on serpro for each row when ((select _id from profile where _id = new._id) is null) begin select raise(abort, 'update on table \"serpro\" violates foreign key constraint \"fk_idspp\"'); end;"; 
    /*"CREATE TRIGGER SERPRO_UP BEFORE UPDATE ON serpro FOR EACH ROW BEGIN SELECT CASE WHEN ((SELECT _id FROM profile WHERE _id = NEW._id) IS NULL ) THEN RAISE (ABORT, ‘update on table serpro violates foreign key constraint fk_idspp’) END; END;";*/

    private static final String TRIGGER_SERPRO_DP = "create trigger serpro_dp before delete on profile for each row begin select raise(abort, 'delete on table \"profile\" violates foreign key constraint \"fk_idspp\" on \"serpro\"') where (select _idp from serpro where _idp = old._id) is not null; end;";
    /*"CREATE TRIGGER SERPRO_DP BEFORE DELETE ON profile FOR EACH ROW BEGIN SELECT CASE WHEN ((SELECT _id FROM serpro WHERE _id = OLD._id) IS NULL ) THEN RAISE (ABORT, ‘delete on table profile violates foreign key constraint fk_idspp’) END; END;";*/


    private static final String TRIGGER_SERPRO_IS = "create trigger serpro_is before insert on serpro for each row when ((select _id from server where _id = new._id) is null) begin select raise(abort, 'insert on table \"serpro\" violates foreign key constraint \"fk_idsps\"'); end;";
    /*"CREATE TRIGGER SERPRO_IS BEFORE INSERT ON serpro FOR EACH ROW BEGIN SELECT CASE WHEN ((SELECT _id FROM server WHERE _id = NEW._id) IS NULL ) THEN RAISE (ABORT, ‘insert on table serpro violates foreign key constraint fk_idsps’) END; END;";*/

    private static final String TRIGGER_SERPRO_US = "create trigger serpro_us before update on serpro for each row when ((select _id from server where _id = new._id) is null) begin select raise(abort, 'update on table \"serpro\" violates foreign key constraint \"fk_idsps\"'); end;";
    /*"CREATE TRIGGER SERPRO_US BEFORE UPDATE ON serpro FOR EACH ROW BEGIN SELECT CASE WHEN ((SELECT _id FROM server WHERE _id = NEW._id) IS NULL ) THEN RAISE (ABORT, ‘update on table serpro violates foreign key constraint fk_idsps’) END; END;";*/

    private static final String TRIGGER_SERPRO_DS = "create trigger serpro_ds before delete on server for each row when ((select _ids from serpro where _ids = old._id) is not null) begin select raise(abort, 'delete on table \"server\" violates foreign key constraint \"fk_idsps\" on \"server\"'); end;";
    /*"CREATE TRIGGER PROFILE_DS BEFORE DELETE ON server FOR EACH ROW BEGIN SELECT CASE WHEN ((SELECT _id FROM serpro WHERE _id = OLD._id) IS NULL ) THEN RAISE (ABORT, ‘delete on table server violates foreign key constraint fk_idsps’) END; END;";*/


    /*private static final String DATABASE_CREATE =
            "create table userdata (_id integer primary key autoincrement, "
                    + "ip string not null, port string not null, query string not null, calendar string not null);";*/

    private static final String DATABASE_NAME = "data";
    //private static final String DATABASE_TABLE = "remoteirdata";
    private static final int DATABASE_VERSION = 2;

    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) {
            db.execSQL(DATABASE_CREATE_SERVER);
            db.execSQL(DATABASE_CREATE_PROFILE);
            db.execSQL(DATABASE_CREATE_SERPRO);
            db.execSQL(TRIGGER_SERPRO_IP);
            db.execSQL(TRIGGER_SERPRO_UP);
            db.execSQL(TRIGGER_SERPRO_DP);
            db.execSQL(TRIGGER_SERPRO_IS);
            db.execSQL(TRIGGER_SERPRO_US);
            db.execSQL(TRIGGER_SERPRO_DS);  
        }

        @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 server");
            db.execSQL("DROP TABLE IF EXISTS profile");
            db.execSQL("DROP TABLE IF EXISTS serpro");
            onCreate(db);
        }
    }

    public RemoteIrDbAdapter(Context ctx) {
        this.mCtx = ctx;
    }

    public RemoteIrDbAdapter open() throws SQLException {
        mDbHelper = new DatabaseHelper(mCtx);
        mDb = mDbHelper.getWritableDatabase();
        return this;
    }

    public void close() {
        mDbHelper.close();
    }


    public long createQueryDataServer(String ip, String port, String server) {
        ContentValues initialValues = new ContentValues();
        initialValues.put(KEY_IP, ip);
        initialValues.put(KEY_PORT, port);
        initialValues.put(KEY_NAMESERVER, server);

        return mDb.insert(DATABASE_TABLE_SERVER, null, initialValues);
    }

    public long createQueryDataProfile(String profile) {
        ContentValues initialValues = new ContentValues();
        initialValues.put(KEY_NAMEPROFILE, profile);

        return mDb.insert(DATABASE_TABLE_PROFILE, null, initialValues);
    }

    public long createQueryDataSerpro(Integer _id, Integer _idp) {
        ContentValues initialValues = new ContentValues();
        initialValues.put(KEY_ROWIDSERVER, _id);
        initialValues.put(KEY_ROWIDPROFILE, _idp);

        return mDb.insert(DATABASE_TABLE_SERPRO, null, initialValues);
    }

    public boolean deleteQueryDataServer(long rowId) {

        return mDb.delete(DATABASE_TABLE_SERVER, KEY_ROWIDSERVER + "=" + rowId, null) > 0;
    }

    public boolean deleteQueryDataProfile(long rowId) {

        return mDb.delete(DATABASE_TABLE_PROFILE, KEY_ROWIDPROFILE + "=" + rowId, null) > 0;
    }


    public Cursor fetchServer(long rowId) throws SQLException {

        Cursor mCursor =

                mDb.query(true, DATABASE_TABLE_SERVER, new String[] {KEY_ROWIDSERVER,
                        KEY_IP, KEY_PORT, KEY_NAMESERVER}, KEY_ROWIDSERVER + "=" + rowId, null,
                        null, null, null, null);
        if (mCursor != null) {
            mCursor.moveToFirst();
        }
        return mCursor;

    }

    public Cursor fetchAllQueryDataServer() {
        return mDb.query(DISTINCT, DATABASE_TABLE_SERVER, new String[] {KEY_ROWIDSERVER,KEY_IP, KEY_PORT, KEY_NAMESERVER}, null, null, null, null, null, null);   
    }

    public Cursor fetchAllQueryDataProfile() {
        return mDb.query(DISTINCT, DATABASE_TABLE_PROFILE, new String[] {KEY_ROWIDPROFILE,KEY_NAMEPROFILE}, null, null, null, null, null, null);   
    }

    public Cursor fetchAllQueryDataAutoCompleteIp(){

        return mDb.query(DISTINCT, DATABASE_TABLE_SERVER, new String[] {KEY_ROWIDSERVER, KEY_IP}, null, null, KEY_IP, null, null, null);    
    }

    public Cursor fetchAllQueryDataAutoCompletePort(){

        return mDb.query(DISTINCT, DATABASE_TABLE_SERVER, new String[] {KEY_ROWIDSERVER, KEY_PORT}, null, null, KEY_PORT, null, null, null);    
    }

    public Cursor fetchAllQueryDataAutoCompleteServerName(){

        //return mDb.query(DISTINCT, DATABASE_TABLE_SERVER, new String[] {KEY_ROWIDSERVER, KEY_NAMESERVER}, null, null, KEY_NAMESERVER, null, null, null);  

        return mDb.rawQuery("SELECT DISTINCT server, _id as _id from server order by _id", null);   
    }

    public Cursor fetchAllQueryDataAutoCompleteProfileName(){

    //      return mDb.query(DISTINCT, DATABASE_TABLE_PROFILE, new String[] {KEY_ROWIDPROFILE, KEY_NAMEPROFILE}, null, null, KEY_NAMEPROFILE, null, null, null);    
            //"SELECT DISTINCT (ip, _id) FROM userdata ORDER BY ip";

        return mDb.rawQuery("SELECT DISTINCT profile, _id from profile order by _id", null);    

        //return mDb.rawQuery("SELECT DISTINCT profile, _id as _id from profile order by _id", null);   
    } 



    public Cursor fetchAllQueryData() {

        return mDb.query(DISTINCT, DATABASE_TABLE_SERVER, new String[] {KEY_ROWIDSERVER,KEY_IP, KEY_PORT, KEY_NAMESERVER}, null, null, null, null, null, null);           
    }

    public Cursor fetchAllServersNotOnProfileData(long idProfile ){

        String sqlstart = "SELECT server.server FROM server INNER JOIN ( serpro INNER JOIN profile ON serpro._id = profile._id WHERE profile._id NOT LIKE '"; 
        String sqlend = "')ON server._id = serpro._id;";
        String sql = sqlstart + idProfile + sqlend;     

        return mDb.rawQuery(sql, null);

    }

 public Cursor fetchAllServersOnProfileData(long idProfile ){

        String sqlstart = "SELECT server.server FROM server INNER JOIN ( serpro INNER JOIN profile ON serpro._id = profile._id WHERE profile._id LIKE '"; 
        String sqlend = "')ON server._id = serpro._id;";
        String sql = sqlstart + idProfile + sqlend;     

        return mDb.rawQuery(sql, null);

    }

    public boolean updateServerData(long rowId, String ip, String port, String server) {
        ContentValues args = new ContentValues();
        args.put(KEY_IP, ip);
        args.put(KEY_PORT, port);
        args.put(KEY_NAMESERVER, server);

        return mDb.update(DATABASE_TABLE_SERVER, args, KEY_ROWIDSERVER + "=" + rowId, null) > 0;
    }

    public boolean updateProfileData(long rowId, String profile) {
        ContentValues args = new ContentValues();
        args.put(KEY_NAMEPROFILE, profile);

        return mDb.update(DATABASE_TABLE_PROFILE, args, KEY_ROWIDPROFILE + "=" + rowId, null) > 0;
    }


}

错误是这样的：

05-14 10:07:46.766: ERROR/AndroidRuntime(324): Uncaught handler: thread main exiting due to uncaught exception
05-14 10:07:46.776: ERROR/AndroidRuntime(324): java.lang.RuntimeException: Unable to start activity ComponentInfo{citic.android.remoteir/citic.android.remoteir.ServerEdit}: android.database.CursorIndexOutOfBoundsException: Index 0 requested, with a size of 0
05-14 10:07:46.776: ERROR/AndroidRuntime(324):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2401)
05-14 10:07:46.776: ERROR/AndroidRuntime(324):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2417)
05-14 10:07:46.776: ERROR/AndroidRuntime(324):     at android.app.ActivityThread.access$2100(ActivityThread.java:116)
05-14 10:07:46.776: ERROR/AndroidRuntime(324):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1794)
05-14 10:07:46.776: ERROR/AndroidRuntime(324):     at android.os.Handler.dispatchMessage(Handler.java:99)
05-14 10:07:46.776: ERROR/AndroidRuntime(324):     at android.os.Looper.loop(Looper.java:123)
05-14 10:07:46.776: ERROR/AndroidRuntime(324):     at android.app.ActivityThread.main(ActivityThread.java:4203)
05-14 10:07:46.776: ERROR/AndroidRuntime(324):     at java.lang.reflect.Method.invokeNative(Native Method)
05-14 10:07:46.776: ERROR/AndroidRuntime(324):     at java.lang.reflect.Method.invoke(Method.java:521)
05-14 10:07:46.776: ERROR/AndroidRuntime(324):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:791)
05-14 10:07:46.776: ERROR/AndroidRuntime(324):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:549)
05-14 10:07:46.776: ERROR/AndroidRuntime(324):     at dalvik.system.NativeStart.main(Native Method)
05-14 10:07:46.776: ERROR/AndroidRuntime(324): Caused by: android.database.CursorIndexOutOfBoundsException: Index 0 requested, with a size of 0
05-14 10:07:46.776: ERROR/AndroidRuntime(324):     at android.database.AbstractCursor.checkPosition(AbstractCursor.java:580)
05-14 10:07:46.776: ERROR/AndroidRuntime(324):     at android.database.AbstractWindowedCursor.checkPosition(AbstractWindowedCursor.java:172)
05-14 10:07:46.776: ERROR/AndroidRuntime(324):     at android.database.AbstractWindowedCursor.getString(AbstractWindowedCursor.java:41)
05-14 10:07:46.776: ERROR/AndroidRuntime(324):     at citic.android.remoteir.ServerEdit.populateFields(ServerEdit.java:57)
05-14 10:07:46.776: ERROR/AndroidRuntime(324):     at citic.android.remoteir.ServerEdit.onCreate(ServerEdit.java:41)
05-14 10:07:46.776: ERROR/AndroidRuntime(324):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1123)
05-14 10:07:46.776: ERROR/AndroidRuntime(324):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2364)

谢谢大家，我对此非常绝望：s

Answer 1

您的查询返回 0 行，这就是您在尝试使用 0 行游标的第一行时收到错误的原因。

您可能希望记录您尝试使用的 _id 值，看看它是否有意义。您还可以将数据库从模拟器下载到开发计算机以检查其内容。