是一个嵌入式数据库,占资源少,支持关系型数据库。Android系统采用了此数据库,有关操作的类有SQLiteDatabase 和接口SQLiteOpenHelper。建立应用程序与sqlite的连接,以及对其库中数据操作关键代码如下:
1、//实现接口SQLiteOpenHelper的类 ,其中的构造函数
public DatabaseHelper(Context context,String name,CursorFactory factory, int version) { super(context,name,factory,version); // TODO Auto-generated constructor stub }
2、//重写onCreate函数
public void onCreate(SQLiteDatabase db) { // TODO Auto-generated method stub db.execSQL("create table user(id int,name varchar(20))");
}
3、创建数据库的关键代码
class CreateOnClick implements OnClickListener { @Override public void onClick(View arg0) { // TODO Auto-generated method stub DatabaseHelper dbHelper = new DatabaseHelper(SQliteActivity.this,"test_db"); SQLiteDatabase db = dbHelper.getReadableDatabase(); } }
4、更新数据库的关键代码
class UpdateOnClick implements OnClickListener { @Override public void onClick(View v) { // TODO Auto-generated method stub DatabaseHelper dbHelper = new DatabaseHelper(SQliteActivity.this,"test_db",null,2); SQLiteDatabase db = dbHelper.getReadableDatabase(); } }
5、插入数据表数据的关键代码
class InsertOnClick implements OnClickListener { @Override public void onClick(View v) { // TODO Auto-generated method stub ContentValues values = new ContentValues(); values.put("id",1); values.put("name","zhao"); DatabaseHelper dbHelper = new DatabaseHelper(SQliteActivity.this,"test_db"); SQLiteDatabase db = dbHelper.getWritableDatabase(); db.insert("user",values); }
6、删除数据表数据的关键代码
class DeleteOnClick implements OnClickListener { @Override public void onClick(View v) { // TODO Auto-generated method stub DatabaseHelper dbHelper = new DatabaseHelper(SQliteActivity.this,"test_db"); SQLiteDatabase db = dbHelper.getWritableDatabase(); db.delete("user","name='zhao'",null); System.out.println("record delete"); } }
7、更新数据表数据的关键代码
class UpdatingOnClick implements OnClickListener { @Override public void onClick(View v) { // TODO Auto-generated method stub ContentValues values = new ContentValues(); values.put("name","zhangsan"); DatabaseHelper dbHelper = new DatabaseHelper(SQliteActivity.this,"test_db"); SQLiteDatabase db = dbHelper.getWritableDatabase(); db.update("user",values,"id=?",new String[]{"1"}); } }
8、查询数据表中数据的关键代码
class QueryOnClick implements OnClickListener { @Override public void onClick(View v) { // TODO Auto-generated method stub DatabaseHelper dbHelper = new DatabaseHelper(SQliteActivity.this,"test_db"); SQLiteDatabase db = dbHelper.getWritableDatabase(); Cursor cursor = db.query ("user",new String[]{"id","name"},new String[]{"1"},null); while(cursor.moveToNext()) { String name = cursor.getString(cursor.getColumnIndex("name")); System.out.print("query----->" + name); } } } (编辑:李大同)
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