我编写了一个程序，可以通过光标显示存储在列表视图中的数据库中的数据。但在运行时它给了我强制关闭。这是我的 logcat 和代码，当我在设备中运行应用程序时，它给我强制关闭，当我更改名称时db，问题解决！！我说之前的BB.sqlite是在另一个页面中创建的。它与这个页面有冲突吗？
这是我的日志：
12-28 04:45:02.950: E/jdwp(22457): Failed sending reply to debugger: Broken pipe
12-28 04:46:04.390: E/AndroidRuntime(22457): FATAL EXCEPTION: AsyncTask #1
12-28 04:46:04.390: E/AndroidRuntime(22457): java.lang.RuntimeException: An error occured while executing doInBackground()
12-28 04:46:04.390: E/AndroidRuntime(22457): at android.os.AsyncTask$3.done(AsyncTask.java:200)
12-28 04:46:04.390: E/AndroidRuntime(22457): at java.util.concurrent.FutureTask$Sync.innerSetException(FutureTask.java:274)
12-28 04:46:04.390: E/AndroidRuntime(22457): at java.util.concurrent.FutureTask.setException(FutureTask.java:125)
12-28 04:46:04.390: E/AndroidRuntime(22457): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:308)
12-28 04:46:04.390: E/AndroidRuntime(22457): at java.util.concurrent.FutureTask.run(FutureTask.java:138)
12-28 04:46:04.390: E/AndroidRuntime(22457): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1088)
12-28 04:46:04.390: E/AndroidRuntime(22457): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:581)
12-28 04:46:04.390: E/AndroidRuntime(22457): at java.lang.Thread.run(Thread.java:1019)
12-28 04:46:04.390: E/AndroidRuntime(22457): Caused by: android.database.sqlite.SQLiteException: no such column: _id: , while compiling: SELECT _id, Good_Name, Good_UnitPrice FROM Tbl_Goods ORDER BY _id ASC
12-28 04:46:04.390: E/AndroidRuntime(22457): at android.database.sqlite.SQLiteCompiledSql.native_compile(Native Method)
12-28 04:46:04.390: E/AndroidRuntime(22457): at android.database.sqlite.SQLiteCompiledSql.compile(SQLiteCompiledSql.java:92)
12-28 04:46:04.390: E/AndroidRuntime(22457): at android.database.sqlite.SQLiteCompiledSql.<init>(SQLiteCompiledSql.java:65)
12-28 04:46:04.390: E/AndroidRuntime(22457): at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:83)
12-28 04:46:04.390: E/AndroidRuntime(22457): at android.database.sqlite.SQLiteQuery.<init>(SQLiteQuery.java:49)
12-28 04:46:04.390: E/AndroidRuntime(22457): at android.database.sqlite.SQLiteDirectCursorDriver.query(SQLiteDirectCursorDriver.java:42)
12-28 04:46:04.390: E/AndroidRuntime(22457): at android.database.sqlite.SQLiteDatabase.rawQueryWithFactory(SQLiteDatabase.java:1364)
12-28 04:46:04.390: E/AndroidRuntime(22457): at android.database.sqlite.SQLiteQueryBuilder.query(SQLiteQueryBuilder.java:330)
12-28 04:46:04.390: E/AndroidRuntime(22457): at android.database.sqlite.SQLiteQueryBuilder.query(SQLiteQueryBuilder.java:280)
12-28 04:46:04.390: E/AndroidRuntime(22457): at com.example.nfc.SqlHelper.getCursor(SqlHelper.java:97)
12-28 04:46:04.390: E/AndroidRuntime(22457): at com.example.nfc.current_cart$SelectDataTask.doInBackground(current_cart.java:90)
12-28 04:46:04.390: E/AndroidRuntime(22457): at com.example.nfc.current_cart$SelectDataTask.doInBackground(current_cart.java:1)
12-28 04:46:04.390: E/AndroidRuntime(22457): at android.os.AsyncTask$2.call(AsyncTask.java:185)
12-28 04:46:04.390: E/AndroidRuntime(22457): at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:306)
12-28 04:46:04.390: E/AndroidRuntime(22457): ... 4 more
当前购物车代码：
public class current_cart extends ListActivity {
private ListView mainListView = null;
CustomSqlCursorAdapter adapter = null;
private SqlHelper dbHelper = null;
private Cursor currentCursor = null;
private ListView listView = null;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.current_cart);
if (this.dbHelper == null) {
this.dbHelper = new SqlHelper(this);
}
listView = getListView();
listView.setItemsCanFocus(false);
listView.setChoiceMode(ListView.CHOICE_MODE_MULTIPLE);
//listView.setClickable(true);
Button btnClear = (Button) findViewById(R.id.btnClear);
btnClear.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
Toast.makeText(getApplicationContext(),
" You clicked Clear button", Toast.LENGTH_SHORT).show();
// ClearDBSelections();
}
});
new SelectDataTask().execute();
this.mainListView = getListView();
mainListView.setCacheColorHint(0);
}
@Override
protected void onRestart() {
super.onRestart();
new SelectDataTask().execute();
}
@Override
protected void onPause() {
super.onPause();
this.dbHelper.close();
}
//protected void ClearDBSelections() {
// this.adapter.ClearSelections();
// }
private class SelectDataTask extends AsyncTask<Void, Void, String> {
protected String doInBackground(Void... params) {
try {
current_cart.this.dbHelper.createDatabase(dbHelper.dbSqlite);
current_cart.this.dbHelper.openDataBase();
current_cart.this.currentCursor = current_cart.this.dbHelper
.getCursor();
} catch (SQLException sqle) {
throw sqle;
}
return null;
}
// can use UI thread here
protected void onPostExecute(final String result) {
startManagingCursor(current_cart.this.currentCursor);
int[] listFields = new int[] { R.id.txtTitle };
String[] dbColumns = new String[] { SqlHelper.COLUMN_TITLE };
current_cart.this.adapter = new CustomSqlCursorAdapter(
current_cart.this, R.layout.single_item,
current_cart.this.currentCursor, dbColumns, listFields,
current_cart.this.dbHelper);
setListAdapter(current_cart.this.adapter);
}
}
}
CustomSqlCursorAdapter 代码：
public class CustomSqlCursorAdapter extends SimpleCursorAdapter {
private Context mContext;
private SqlHelper mDbHelper;
private Cursor mCurrentCursor;
public CustomSqlCursorAdapter(Context context, int layout, Cursor c,
String[] from, int[] to, SqlHelper dbHelper) {
super(context, layout, c, from, to);
this.mCurrentCursor = c;
this.mContext = context;
this.mDbHelper = dbHelper;
}
public View getView(int pos, View inView, ViewGroup parent) {
View v = inView;
if (v == null) {
LayoutInflater inflater = (LayoutInflater) mContext
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
v = inflater.inflate(R.layout.single_item, null);
}
if (!this.mCurrentCursor.moveToPosition(pos)) {
throw new SQLException("CustomSqlCursorAdapter.getView: Unable to move to position: "+pos);
}
CheckBox cBox = (CheckBox) v.findViewById(R.id.bcheck);
cBox.setTag(Integer.valueOf(this.mCurrentCursor.getInt(0)));
cBox.setOnCheckedChangeListener(new OnCheckedChangeListener() {
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
}
});
TextView txtTitle = (TextView) v.findViewById(R.id.txtTitle);
txtTitle.setText(this.mCurrentCursor.getString(this.mCurrentCursor
.getColumnIndex(SqlHelper.COLUMN_TITLE)));
return (v);
}
}
SqlHelper 代码：
public class SqlHelper extends SQLiteOpenHelper {
private static final String DATABASE_PATH = "/data/data/com.example.nfc/databases/";
public static final String DATABASE_NAME = "BB.sqlite";
public static final String TABLE_NAME = "Tbl_Goods";
public static final int ToDoItems_VERSION = 1;
public static final String COLUMN_ID = "_id"; // 0
public static final String COLUMN_TITLE = "Good_Name"; // 1
public static final String COLUMN_NAME_DESC = "Good_UnitPrice";// 2
// public static final String COLUMN_SELECTED = "selected"; // 3
// public static final int COLUMN_SELECTED_idx = 3;
public SQLiteDatabase dbSqlite;
private Context mContext;
public SqlHelper(Context context) {
super(context, DATABASE_NAME, null, 1);
mContext = context;
}
@Override
public void onCreate(SQLiteDatabase db) {
createDB(db);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
Log.w("SqlHelper", "Upgrading database from version " + oldVersion
+ " to " + newVersion + ", which will destroy all old data");
db.execSQL("DROP TABLE IF EXISTS Tbl_Goods;");
createDB(db);
}
public void createDatabase(SQLiteDatabase db) {
createDB(db);
}
private void createDB(SQLiteDatabase db) {
// if (db == null) {
db = mContext.openOrCreateDatabase(DATABASE_NAME, 0, null);
// }
db.execSQL("CREATE TABLE IF NOT EXISTS Tbl_Goods (_id INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL DEFAULT 1,Good_ID INTEGER NOT NULL ,Cart_ID INTEGER, Good_Name VARCHAR(50),Good_UnitPrice INTEGER (10),Quantity INTEGER);");
db.setVersion(ToDoItems_VERSION);
//
// Generate a few rows for an example
//
// find out how many rows already exist, and make sure there's some minimum
// SQLiteStatement s = db.compileStatement("select count(*) from ToDoItems;");
// long count = s.simpleQueryForLong();
// for (int i = 0; i < 20-count; i++) {
// db.execSQL("INSERT INTO ToDoItems VALUES(NULL,'Task #"+i+"','Description #"+i+"');");
// }
}
public void openDataBase() throws SQLException {
String myPath = DATABASE_PATH + DATABASE_NAME;
dbSqlite = SQLiteDatabase.openDatabase(myPath, null,
SQLiteDatabase.OPEN_READWRITE);
}
@Override
public synchronized void close() {
if (dbSqlite != null)
dbSqlite.close();
super.close();
}
public Cursor getCursor() {
SQLiteQueryBuilder queryBuilder = new SQLiteQueryBuilder();
queryBuilder.setTables(TABLE_NAME);
String[] asColumnsToReturn = new String[] { COLUMN_ID,COLUMN_TITLE,
COLUMN_NAME_DESC };
Cursor mCursor = queryBuilder.query(dbSqlite, asColumnsToReturn, null,
null, null, null, COLUMN_ID+" ASC");
return mCursor;
}
// public void clearSelections() {
// ContentValues values = new ContentValues();
// values.put(COLUMN_SELECTED, 0);
// this.dbSqlite.update(SqlHelper.TABLE_NAME, values, null, null);
// }
}
另一个我的页面使用此代码来使用数据库：
private static String DB_NAME = "BB.sqlite";
public static final String COLUMN_ID = "_id";
public static final String CartID = "Cart_ID";
public static final String GoodID = "Good_ID";
public static final String GoodName = "Good_Name";
public static final String DATABASE_TABLE = "Tbl_Goods";
public static final String DATABASE_CREATE =
//_id INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL DEFAULT 1,
"CREATE TABLE Tbl_Goods (_id INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL DEFAULT 1,Good_ID INTEGER NOT NULL ,Cart_ID INTEGER, Good_Name VARCHAR(50),Good_UnitPrice INTEGER (10),Quantity INTEGER);";
public static final String DATABASE_CREATE2 = "CREATE TABLE Tbl_Cart (Cart_ID INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL DEFAULT 1,"+" Cart_Date DATETIME ,"+" Cart_Start_Time DATETIME ,"+" Cart_End_Time DATETIME,"+" Cart_Total INTEGER (10),"+" Cart_Status INTEGER);";
private static final String Good_Name = null;
private static final String Quantity = null;
private static final String Good_UnitPrice = null;
private java.util.Date _Date;
// private DatabaseHelper DBHelper;
private SQLiteDatabase db;
// private SQLiteDatabase db;
// the extension may be .sqlite
// or .db
// public SQLiteDatabase myDataBase;
public DBAdapter(Context context) {
super(context, DB_NAME, null, 1);
this.mycontext = context;
}
public void createDataBase() throws IOException{
boolean dbExist = checkDataBase();
if(dbExist){
//do nothing - database already exist
}else{
//By calling this method and empty database will be created into the default system path
//of your application so we are gonna be able to overwrite that database with our database.
this.getReadableDatabase();
try {
copyDataBase();
} catch (IOException e) {
throw new Error("Error copying database");
}
}
}
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;
}
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 DBAdapter open() throws SQLException
{
String myPath = DB_PATH + DB_NAME;
db = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READWRITE);
return this;
}
public DBAdapter open1() throws SQLException
{
String myPath = DB_PATH + DB_NAME;
db = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);
return this;
}
@Override
public synchronized void close() {
if(db != null)
db.close();
super.close();
}
@Override
public void onCreate(SQLiteDatabase db)
{
// db.execSQL(DATABASE_CREATE);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
}
public void Cancel()
{
ContentValues args = new ContentValues();
args.put(CartStatus, 2);
db.update(DATABASE_TABLE2, args, CartID + "=" + lastId, null);
}
}