在我的应用程序中，我使用数据库显示一些用户信息，我使用SQLite数据库浏览器创建数据库，并将该数据库放在assets文件夹中，这是编码，我想显示此表
public class DataBaseHelper extends SQLiteOpenHelper{
private Context mycontext;
private String DB_PATH = "/data/data/com.slate.game/databases/";
private static String DB_NAME = "slider.db";//the extension may be .sqlite or .db
public SQLiteDatabase myDataBase;
public DataBaseHelper(Context context) throws IOException {
super(context,DB_NAME,null,1);
this.mycontext=context;
boolean dbexist = checkdatabase();
if(dbexist) {
System.out.println("Database exists");
opendatabase();
}
else {
System.out.println("Database doesn't exist");
createdatabase();
}
}
public void createdatabase() throws IOException{
boolean dbexist = checkdatabase();
if(dbexist) {
System.out.println(" Database exists.");
}
else{ this.getReadableDatabase();
try{
copydatabase();
}
catch(IOException e) {
throw new Error("Error copying database");
}
}
}
private boolean checkdatabase() {
boolean checkdb = false;
try {
String myPath = DB_PATH + DB_NAME;
File dbfile = new File(myPath);
checkdb = dbfile.exists();
}
catch(SQLiteException e) {
System.out.println("Database doesn't exist");
}
return checkdb;
}
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;
System.out.println("outfilename"+outfilename);
//Open the empty db as the output stream
OutputStream myoutput = new FileOutputStream("/data/data/com.slate.game/databases/slider.db");
// transfer byte to inputfile to 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 void opendatabase() throws SQLException {
//Open the database
String mypath = DB_PATH + DB_NAME;
myDataBase = SQLiteDatabase.openDatabase(mypath, null, SQLiteDatabase.OPEN_READWRITE);
}
public synchronized void close() {
if(myDataBase != null){
myDataBase.close();
}
super.close();
}
@Override
public void onCreate(SQLiteDatabase arg0) {
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
}
请帮我看看如何显示这个表（数据库）..
答案 0 :(得分：4)
最后我从这本书中得到了答案
Beginning.Android.Application.Development.
使用SQLite我准备的数据库，我会得到行和显示使用TableLayout和TextView ..
这是数据库适配器类
public class DBAdapter3x3 {
public static final String KEY_ROWID = "_id";
public static final String KEY_NAME = "name";
public static final String KEY_MOVES = "moves";
public static final String KEY_TIME = "time";
private static final String TAG = "DBAdapter";
private static final String DATABASE_NAME = "SliderDB3x3.db";
private static final String DATABASE_TABLE = "topscore3x3";
private static final int DATABASE_VERSION = 1;
private static final String DATABASE_CREATE = "create table topscore3x3 " +
"(_id integer primary key autoincrement, "
+ "name text not null, moves integer not null,"
+ "time text not null);";
private final Context context;
private DatabaseHelper DBHelper;
private SQLiteDatabase db;
public DBAdapter3x3(Context ctx) {
this.context = ctx;
DBHelper = new DatabaseHelper(context);
}
private static class DatabaseHelper extends SQLiteOpenHelper {
DatabaseHelper(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
try {
db.execSQL(DATABASE_CREATE);
} catch (SQLException e) {
e.printStackTrace();
}
}
@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 contacts");
onCreate(db);
}
}
//---opens the database---
public DBAdapter3x3 open() throws SQLException {
db = DBHelper.getWritableDatabase();
return this;
}
//---closes the database---
public void close() {
DBHelper.close();
}
//---insert a contact into the database---
public long insertContact(String name, int moves,String time) {
ContentValues initialValues = new ContentValues();
initialValues.put(KEY_NAME, name);
initialValues.put(KEY_MOVES, moves);
initialValues.put(KEY_TIME, time);
return db.insert(DATABASE_TABLE, null, initialValues);
}
//---deletes a particular contact---
public boolean deleteContact(long rowId) {
return db.delete(DATABASE_TABLE, KEY_ROWID + "=" + rowId, null) > 0;
}
//---retrieves all the contacts---
public Cursor getAllContacts() {
return db.query(DATABASE_TABLE, new String[] {KEY_ROWID, KEY_NAME,
KEY_MOVES, KEY_TIME}, null, null, null, null, null);
}
//---retrieves a particular contact---
public Cursor getContact(long rowId) throws SQLException {
Cursor mCursor = db.query(true, DATABASE_TABLE, new String[] {KEY_ROWID, KEY_NAME,
KEY_MOVES, KEY_TIME}, KEY_ROWID + "=" + rowId, null,null, null, null, null);
if (mCursor != null) {
mCursor.moveToFirst();
}
return mCursor;
}
//---updates a contact---
public boolean updateContact(long rowId, String name, int moves, String time) {
ContentValues args = new ContentValues();
args.put(KEY_NAME, name);
args.put(KEY_MOVES, moves);
args.put(KEY_TIME, time);
return db.update(DATABASE_TABLE, args, KEY_ROWID + "=" + rowId, null) > 0;
}
//public Cursor fetchAllNotes() {
public Cursor SortAllRows() {
return db.query(DATABASE_TABLE, new String[] { KEY_ROWID, KEY_NAME,
KEY_MOVES,KEY_TIME}, null, null, null, null, KEY_MOVES + " ASC");
}
}
我在此活动中使用了数据库
public class TopScore3x3 extends Activity {
private DBAdapter3x3 db;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.db3x3);
db = new DBAdapter3x3(this);
getall();
delete();
private void delete() {
db.open();
Cursor c = db.SortAllRows();
int i=1;
if (c.moveToFirst()) {
do {
if(i>10) { db.deleteContact(i); }
i++;
} while (c.moveToNext());
}
c.close();
db.close();
}
private void getall() {
//---get all contacts---
db.open();
//db.fetchAllNotes();
Cursor c = db.SortAllRows();
int i=1;
if (c.moveToFirst()) {
do {
DisplayContact(c,i++);
} while (c.moveToNext());
}
c.close();
db.close();
}
public void DisplayContact(Cursor c,int row ) {
String name11 = c.getString(1) + c.getString(2) + c.getString(3);
tv1.setText(name11 );
}
}
答案 1 :(得分：1)
使用以下函数从数据库中检索数据
/**
* This function used to select the records from DB.
* @param tableName
* @param tableColumns
* @param whereClase
* @param whereArgs
* @param groupBy
* @param having
* @param orderBy
* @return A Cursor object, which is positioned before the first entry.
*/
public Cursor selectRecordsFromDB(String tableName, String[] tableColumns,String whereClase, String whereArgs[], String groupBy,String having, String orderBy)
{
return myDataBase.query(tableName, tableColumns, whereClase, whereArgs,groupBy, having, orderBy);
}
/**
* select records from db and return in list
* @param tableName
* @param tableColumns
* @param whereClase
* @param whereArgs
* @param groupBy
* @param having
* @param orderBy
* @return ArrayList<ArrayList<String>>
*/
public ArrayList<ArrayList<String>> selectRecordsFromDBList(String tableName, String[] tableColumns,String whereClase, String whereArgs[], String groupBy,String having, String orderBy)
{
ArrayList<ArrayList<String>> retList = new ArrayList<ArrayList<String>>();
ArrayList<String> list = new ArrayList<String>();
Cursor cursor = myDataBase.query(tableName, tableColumns, whereClase, whereArgs,
groupBy, having, orderBy);
if (cursor.moveToFirst())
{
do
{
list = new ArrayList<String>();
for(int i=0; i<cursor.getColumnCount(); i++)
{
list.add( cursor.getString(i) );
}
retList.add(list);
} while (cursor.moveToNext());
}
if (cursor != null && !cursor.isClosed()) {
cursor.close();
}
return retList;
}
答案 2 :(得分：1)
请检查：http://www.higherpass.com/Android/Tutorials/Accessing-Data-With-Android-Cursors/2/
使用Cursor c = db.rawQuery(sql, null)获取结果，在那里解释迭代。