首先写一个helper继承SQLiteOpenHelper
private SQLiteDatabase db_r = null; // readable database
private SQLiteDatabase db_w = null; // writable database
private static DbHelper dbHelper;
private DbHelper(Context context) {
super(context, DataBaseClass.DB_FILE, null, DataBaseClass.DB_VERSION);
}
public static synchronized DbHelper getInstance(Context context) {
if (dbHelper == null) {
dbHelper = new DbHelper(context);
}
return dbHelper;
}
@Override
public void onCreate(SQLiteDatabase db) {
Collection<DbBaseTable> tables = DataBaseClass.sRCMDbTables.values();
Iterator<DbBaseTable> iterator = tables.iterator();
System.out.println("====DBHelp oncreate");
try {
db.beginTransaction();
while (iterator.hasNext()) {
iterator.next().onCreate(db);
}
db.setTransactionSuccessful();
} catch (Throwable e) {
throw new RuntimeException("DB creation failed: " + e.getMessage());
} finally {
db.endTransaction();
}
}
@Override
public synchronized SQLiteDatabase getReadableDatabase() {
if (db_r == null || !db_r.isOpen()) {
try {
db_r = super.getReadableDatabase();
} catch (SQLiteException e) {
//TODO Implement proper error handling
db_r = null;
throw e;
}
}
return db_r;
}
@Override
public synchronized SQLiteDatabase getWritableDatabase() {
if (db_w == null || !db_w.isOpen() || db_w.isReadOnly()) {
try {
db_w = super.getWritableDatabase();
} catch (SQLiteException e) {
//TODO Implement proper error handling
db_w = null;
throw e;
}
}
return db_w;
}创建表封装一个类:
public final class DataBaseClass {
private DataBaseClass() {};
public static final int DB_VERSION = 2;
static final String DB_FILE = "my.db";
public interface RCMColumns {
public static final String account_ID = "account_id"; //INTEGER (long)
}
public static final class MyTest1Table extends DbBaseTable implements BaseColumns, RCMColumns {
private MyTest1Table() {
}
private static final MyTest1Table sInstance = new MyTest1Table();
static MyTest1Table getInstance() {
return sInstance;
}
private static final String TABLE_NAME = "Mytest1";
/* Columns */
public static final String TEST1 = "test1";
public static final String TEST2 = "test2";
public static final String TEST3 = "test3";
private static final String CREATE_TABLE_STMT = "CREATE TABLE IF NOT EXISTS "
+ TABLE_NAME + " (" + _ID + " INTEGER PRIMARY KEY AUTOINCREMENT,"
+ account_ID + " INTEGER, "
+ TEST1 + " TEXT, "
// + TEST2 + " TEXT, "
+ TEST3 + " TEXT"
+ ");";
@Override
String getName() {
return TABLE_NAME;
}
@Override
void onCreate(SQLiteDatabase db) {
db.execSQL(CREATE_TABLE_STMT);
}
}
public static final class MyTest2Table extends DbBaseTable implements BaseColumns, RCMColumns {
private MyTest2Table() {
}
private static final MyTest2Table sInstance = new MyTest2Table();
static MyTest2Table getInstance() {
return sInstance;
}
private static final String TABLE_NAME = "Mytest2";
/* Columns */
public static final String TEST4 = "test4";
public static final String TEST5 = "test5";
public static final String TEST6 = "test6";
private static final String CREATE_TABLE_STMT = "CREATE TABLE IF NOT EXISTS "
+ TABLE_NAME + " (" + _ID + " INTEGER PRIMARY KEY AUTOINCREMENT,"
+ account_ID + " INTEGER, "
+ TEST4 + " TEXT, "
+ TEST5 + " TEXT, "
+ TEST6 + " TEXT"
+ ");";
@Override
String getName() {
return TABLE_NAME;
}
@Override
void onCreate(SQLiteDatabase db) {
db.execSQL(CREATE_TABLE_STMT);
}
}
static LinkedHashMap<String, DbBaseTable> sRCMDbTables = new LinkedHashMap<String, DbBaseTable>();
static {
sRCMDbTables.put(MyTest1Table.getInstance().getName(), MyTest1Table.getInstance());
// sRCMDbTables.put(MyTest2Table.getInstance().getName(), MyTest2Table.getInstance());
}
}用一个contentProvider来对数据库进行查询，插入操作:
public class MyProvider extends ContentProvider {
static final boolean DEBUG_ENBL = false;
static final String TAG = "[RC]MyProvider";
/* URI authority string */
public static final String AUTHORITY = "com.pic.optimize.provider.myprovider";
/* URI paths names */
public static final String MyTest1Table = "MyTest1Table";
public static final String MyTest2Table = "MyTest2Table";
private DbHelper dbHelper;
@Override
public boolean onCreate() {
dbHelper = DbHelper.getInstance(getContext());
return true;
}
@Override
public int delete(Uri uri, String selection, String[] selectionArgs) {
return 0;
}
@Override
public String getType(Uri uri) {
return null;
}
@Override
public Uri insert(Uri uri, ContentValues values) {
int match = sUriMatcher.match(uri);
SQLiteDatabase db;
long rowId;
try {
db = dbHelper.getWritableDatabase();
} catch (SQLiteException e) {
throw e;
}
synchronized (dbHelper) {
try {
rowId = db.insert(tableName(match), null, values);
} catch (SQLException e) {
throw e;
}
}
uri = ContentUris.withAppendedId(UriHelper.removeQuery(uri), rowId);
getContext().getContentResolver().notifyChange(uri, null);
return uri;
}
@Override
public Cursor query(Uri uri, String[] projection, String selection,
String[] selectionArgs, String sortOrder) {
int match = sUriMatcher.match(uri);
SQLiteQueryBuilder qb = new SQLiteQueryBuilder();
qb.setTables(tableName(match));
SQLiteDatabase db;
try {
db = dbHelper.getReadableDatabase();
} catch (SQLiteException e) {
// TODO Implement proper error handling
throw e;
}
Cursor cursor;
synchronized (dbHelper) {
try {
cursor = qb.query(db, projection, selection, selectionArgs,
null, null, sortOrder);
} catch (Throwable e) {
throw new RuntimeException("Exception at db query: "
+ e.getMessage());
}
}
return cursor;
}
@Override
public int update(Uri uri, ContentValues values, String selection,
String[] selectionArgs) {
return 0;
}
private String tableName(int uri_match) {
switch (uri_match) {
case MyTest1Table_MATCH:
return DataBaseClass.MyTest1Table.getInstance().getName();
case MyTest2Table_MATCH:
return DataBaseClass.MyTest2Table.getInstance().getName();
}
return null;
}
/* UriMatcher codes */
private static final int MyTest1Table_MATCH = 10;
private static final int MyTest2Table_MATCH = 11;
private static final UriMatcher sUriMatcher = new UriMatcher(UriMatcher.NO_MATCH);
static {
sUriMatcher.addURI(AUTHORITY, MyTest1Table, MyTest1Table_MATCH);
sUriMatcher.addURI(AUTHORITY, MyTest2Table, MyTest2Table_MATCH);
}
}Activity调用:
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
copyDatabase();
DbHelper.getInstance(this);
addDataToDataBase();
queryDataBase1();
}
private void copyDatabase() {
File file = new File("/data/data/com.pic.optimize/databases");
String[] array = file.list();
for(int i=0;i<array.length;i++) {
Log.d("TAG","=====array[i]="+array[i]);
}
File f = new File("/data/data/com.pic.optimize/databases/my.db");
String sdcardPath = Environment.getExternalStorageDirectory().getAbsolutePath();
File o = new File(sdcardPath+"/my.db");
if(f.exists()) {
FileChannel outF;
Log.d("TAG","=====file exsit");
try {
outF = new FileOutputStream(o).getChannel();
new FileInputStream(f).getChannel().transferTo(0, f.length(),outF);
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
Toast.makeText(this, "完成", Toast.LENGTH_SHORT).show();
}
}
private void addDataToDataBase() {
try {
ContentResolver resolver = this.getContentResolver();
ContentValues values = new ContentValues();
values.put(DataBaseClass.MyTest1Table.TEST1, "cc");
values.put(DataBaseClass.MyTest1Table.account_ID, 1002);
resolver.insert(UriHelper.getUri(MyProvider.MyTest1Table),
values);
} catch (Throwable error) {
}
}
private void queryDataBase1() {
ContentResolver resolver = this.getContentResolver();
Cursor cursor = resolver.query(UriHelper.getUri(MyProvider.MyTest1Table), null, null, null, null);
cursor.moveToPosition(-1);
while(cursor.moveToNext()) {
int account = cursor.getInt(1);
String test1 = cursor.getString(2);
}
cursor.close();
}打印结果是:
12-10 10:28:49.580 11294-11294/com.pic.optimize D/TAG: =====array[i]=my.db
12-10 10:28:49.580 11294-11294/com.pic.optimize D/TAG: =====array[i]=my.db-journal
12-10 10:28:49.581 11294-11294/com.pic.optimize D/TAG: =====file exsit
12-10 10:28:49.610 11294-11294/com.pic.optimize I/System.out: ====account=1002test1=cc
随时随地看视频
