Android sqlite 操作
今天开始写博客，写sqlite的基本应用的两个类，包含了基本的CRUD和分页操作。废话不说，代码能直接拷用。参照黎活明老师的讲解public class dataBaseHelper extends SQLiteOpenHelper {
private static final String DBNAME = "shining"; //数据库名称
private static final int VERSION = 1; //数据库版本
public dataBaseHelper(Context context) {
super(context, DBNAME, null, VERSION);
// TODO Auto-generated constructor stub
}
@Override
public void onCreate(SQLiteDatabase db) {
// TODO Auto-generated method stub
//好友:id,name,age,phone
db.execSQL("CREATE TABLE IF NOT EXISTS friends(id integer primary key autoincrement, name varchar(20), age INTEGER,phone varchar(20))");
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
// TODO Auto-generated method stub
db.execSQL("DROP TABLE IF EXISTS friends");
onCreate(db);
}
}
public class FriendService {
private dataBaseHelper dbHelper;
public FriendService( Context context)
{
dbHelper=new dataBaseHelper(context);
}
public void save(Friend f)
{
SQLiteDatabase db=dbHelper.getWritableDatabase();
db.execSQL("insert into friends(name,age,phone) values(?,?,?)",new Object[]{f.getName(),f.getAge(),f.getPhone()});
db.close();
}
public void update(Friend f)
{
SQLiteDatabase db=dbHelper.getWritableDatabase();
db.execSQL("update friends set name=?,age=?,phone=? where id=?",
new Object[]{f.getName(),f.getAge(),f.getPhone(),f.getId()});
db.close();
}
public Friend find(int id)
{
SQLiteDatabase db=dbHelper.getReadableDatabase();
Cursor cursor=db.rawQuery("select * from friends where id=?",new String[]{String.valueOf(id)});
if(cursor.moveToNext())
{
return new Friend(cursor.getInt(0),cursor.getString(1), cursor.getInt(2), cursor.getString(3));
}
db.close();
return null;
}
public void delete(Integer ...ids)
{
if(ids.length>0)
{
StringBuilder sb=new StringBuilder();
for(int i=0;i<ids.length;i++)
{
sb.append('?').append(',');
}
sb.deleteCharAt(sb.length()-1);
SQLiteDatabase db=dbHelper.getWritableDatabase();
db.execSQL("delete from friends where id in("+sb+")",(Object[])ids);
db.close();
}
}
public List<Friend> getList(int start,int max)
{
List<Friend> list=new ArrayList<Friend>();
SQLiteDatabase db=dbHelper.getWritableDatabase();
Cursor cursor=db.rawQuery("select * from friends limit ?,? ",new String[]{String.valueOf(start),String.valueOf(max)});
while(cursor.moveToNext())
{
list.add(new Friend(cursor.getInt(0),cursor.getString(1), cursor.getInt(2), cursor.getString(3)));
}
db.close();
return list;
}
public long getCount()
{
SQLiteDatabase db=dbHelper.getReadableDatabase();
Cursor cursor=db.rawQuery("select count(*) from friends",null);
if(cursor.moveToNext())
{
return cursor.getLong(0);
}
db.close();
return 0;
}
}
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