首先你需要創建引黃API類與數據庫
public class DatabaseconectionApiDemo extends SQLiteOpenHelper {
private final Context myContext;
ArrayList<String> labels1;
// StaticValues mStaticValues;
private static SQLiteDatabase db;
@SuppressLint("SdCardPath")
public final static String DB_PATH = "/data/data/com....youpackagename..../databases/";
public final static String DB_NAME = "DataBaseName.sqlite";
public DatabaseconectionApiDemo(Context context) {
super(context, DB_NAME, null, 1);
this.myContext = context;
}
public void createDataBase() throws IOException {
boolean dbExist = checkDataBase();
if (dbExist) {
// do nothing
} 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 void copyDataBase() throws IOException{
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[2048];
int length;
while ((length = myInput.read(buffer)) > 0) {
myOutput.write(buffer, 0, length);
}
// Close the streams
myOutput.flush();
myOutput.close();
myInput.close();
}
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;
}
public void openDataBase() throws SQLException {
try {
if (db != null) {
if (db.isOpen()) {
db.close();
}
}
} catch (Exception e) {
System.out.println("no database connected to close");
}
// Open the database
String myPath = DB_PATH + DB_NAME;
db = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READWRITE);
}
@Override
public synchronized void close() {
if (db != null)
db.close();
super.close();
}
public int Update(String TableName, String cols[], String values[], String whereClause, String whereArgs[]) {
int id = 0;
openDataBase();
id = db.update(TableName, getContentValues(cols, values), whereClause, whereArgs);
close();
return id;
}
public int insertwithreturnid(String TableName, String cols[], String values[]) {
int id = 0;
openDataBase();
id = (int) db.insert(TableName, null, getContentValues(cols, values));
close();
return id;
}
public int delete(String TableName, String where, String whereArgs[]) {
int id = 0;
openDataBase();
id = db.delete(TableName, where, whereArgs);
close();
return id;
}
public DataHolder readFromTableName(String TableName, String cols[], String where[], String keyword) {
openDataBase();
DataHolder _holder = null;
Cursor c = null;
c = db.query(TableName, cols, where[0], null, null, null, null);
if (c != null) {
c.moveToFirst();
_holder = new DataHolder();
while (!c.isAfterLast()) {
int count = c.getColumnCount();
_holder.CreateRow();
for (int i = 0; i < count; i++) {
_holder.setmColoumn(c.getColumnName(i), c.getString(i));
}
_holder.AddRow();
c.moveToNext();
}
}
c.close();
close();
return _holder;
}
public void exeQuery(String sql) {
openDataBase();
try {
db.execSQL(sql);
} catch (Exception e) {
System.out.println(e.toString());
}
close();
}
public boolean InsertByValue(String table, ContentValues values) {
try {
openDataBase();
db.insertOrThrow(table, null, values);
Log.d("InsertByValue", "Data Insert");
return true;
} catch (Exception e) {
Log.d("InsertByValue", e.toString());
e.printStackTrace();
return false;
}
}
public DataHolder read(String sql) {
openDataBase();
DataHolder _holder = null;
Cursor c = db.rawQuery(sql, null);
if (c != null) {
c.moveToFirst();
_holder = new DataHolder();
while (!c.isAfterLast()) {
int count = c.getColumnCount();
_holder.CreateRow();
for (int i = 0; i < count; i++) {
_holder.setmColoumn(c.getColumnName(i), c.getString(i));
}
_holder.AddRow();
c.moveToNext();
}
}
c.close();
close();
return _holder;
}
public ContentValues getContentValues(String cols[], String values[]) {
ContentValues cv = new ContentValues();
for (int i = 0; i < cols.length; i++) {
cv.put(cols[i], values[i]);
}
return cv;
}
@Override
public void onCreate(SQLiteDatabase db) {
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
}
}
連接的，你需要從
public class DataHolder {
private ArrayList<LinkedHashMap<String, String>> mRow;
private LinkedHashMap<String, String> mColoumn;
public DataHolder() {
super();
mRow = new ArrayList<LinkedHashMap<String, String>>();
}
public void setmColoumn(String col, String value) {
this.mColoumn.put(col, value);
}
public ArrayList<LinkedHashMap<String, String>> getmRow() {
return mRow;
}
public void CreateRow() {
this.mColoumn = new LinkedHashMap<String, String>();
}
public void AddRow() {
this.mRow.add(this.mColoumn);
}
public void clear() {
this.mRow.clear();
}
public void add(LinkedHashMap<String, String> linkedHashMap) {
this.mRow.add(linkedHashMap);
}
}
添加數據持有類閱讀你的數據和finnaly你可以閱讀，通過以下查詢插入，更新和刪除數據庫表數據
public class YourActivity extends Activity{
private DataHolder mDataHolder;
private DatabaseconectionApi mDatabaseconectionApi;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.your_layout);
// initialize dataholder and connectionapi class like bellow
mDataHolder=new DataHolder();
mDatabaseconectionApi=new DatabaseconectionApi(YourActivity.this);
try {
mDatabaseconectionApi.createDataBase();
mDatabaseconectionApi.openDataBase();
}catch (IOException e) {
e.printStackTrace();
}
...........
//now you can perform insert,update,read and delete like these
mDataHolder = new DataHolder();
mDataHolder = mDatabaseconectionApi.read("SELECT * from table_name where "+table_id
+" = '"+TId+"'");
mDatabaseconectionApi.insertwithreturnid("table_name",
new String[]{"column_name"},
new String[]{"column_value"});
mDatabaseconectionApi.Update("table_name",
new String[]{"column_name"}, new String[]{"column_value"},
"column_id"+" = ?", new String[]{"column_id_value"});
mDatabaseconectionApi.delete("table_name", null, null);
// or
mDatabaseconectionApi.delete("table_name", "column_id"+" = ?", new String[]{"column_id_value"});