使用SQLite数据库<增，删，改，查>

Activity

public class MainActivity extends Activity {

private MySQLiteOpenHeilper mySQLiteOpenHeilper;
private StudentDao studentDao;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        studentDao = new StudentDao(this);
    }

public void insert(View view) {
        Student student = new Student();
        student.setName("张三");
        student.setPwd("1234");     
        studentDao.add(student);


        Student student1 = new Student();
        student1.setName("李四");
        student1.setPwd("543");     
        studentDao.add(student1);

        Student student2 = new Student();
        student2.setName("王五");
        student2.setPwd("1234");        
        studentDao.add(student2);

        Toast.makeText(MainActivity.this,"成功", 0).show();

    }
public void delete(View view) {
        studentDao.delete("李四");

    }
public void update(View view) {
        Student student = new Student();
        student.setName("王五");
// student.setPwd("124235");
// student.setName("王五王五");
        studentDao.update(student);


    }
public void select(View view) {
        List<Student> list = studentDao.select("张三", "1234");
for (int i = 0; i <list.size(); i++) {
            Student student = list.get(i);

                Toast.makeText(MainActivity.this, student.getName()+":"+student.getPwd(), 0).show();
        }

    }
}

SQLite类

public class MySQLiteOpenHeilper extends SQLiteOpenHelper {
/**
 * Context context, //上下文
 * String name, // 数据库 名
 CursorFactory factory, //游标工厂 一般游标初始值是 null
 int version // 版本号 -->(升级的版本号) 默认值最低是1
 */

public MySQLiteOpenHeilper(Context context) {
super(context, "Student.db", null, 1);
    }

@Override
public void onCreate(SQLiteDatabase db) {

        db.execSQL("create table student1(id integer primary key autoincrement ," +
"name varchar (10), pwd varchar(10))");

    }

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {


    }


}

dao包

public class StudentDao {

private MySQLiteOpenHeilper heilper;
private SQLiteDatabase db;
private String stu="student1";
private SQLiteDatabase read;

public StudentDao(Context context){
        heilper = new MySQLiteOpenHeilper(context);
        db = heilper.getWritableDatabase();
        read = heilper.getReadableDatabase();
    }
// 添加的方法
public int add(Student student) {
        ContentValues values = new ContentValues();
        values.put("name", student.getName());
        values.put("pwd", student.getPwd());

int set=(int) db.insert(stu, null, values);


return set;
    }
/**
 * 删除的方法
 */
public void delete(String name) {

        db.delete(stu,"name=?", new String []{name});

    }
/**
 * 修改的方法
 * @return 
 */
public void update(Student student) {



        ContentValues values = new ContentValues();
        values.put("name", "asdjasd");
// values.put("pwd", student.getPwd());

        db.update(stu, values, "name=?", new String[]{student.getName()});  
    }


/**
 * 查询的方法
 */
public List<Student> select(String name,String pwd) {
        ArrayList<Student> list=new ArrayList<Student>();

        Cursor query = read.query(stu, new String[]{"name","pwd"}, "name=? and pwd=?", 
new String[]{name,pwd}, null, null, null);


while (query.moveToNext()) {
                Student student = new Student();

                String string = query.getString(query.getColumnIndex("name"));
                String string2 = query.getString(query.getColumnIndex("pwd"));

                student.setName(string);
                student.setPwd(string2);

                list.add(student);              
            }


return list;
    }
}

内容提供者 ContentProvider

注意：使用SQLite数据库<增，删，改，查> 可以忽略这个

public class MyContentProvipter extends ContentProvider {

private static final String TAG="MyContentProvipter";
private MySQLilteOpenhelper helper;
private  static String USER="user"; 


@Override
public boolean onCreate() {
        helper = new MySQLilteOpenhelper(getContext());

return false;
    }
@Override
public int delete(Uri uri, String selection, String[] selectionArgs) {

        SQLiteDatabase db = helper.getWritableDatabase();
        db.delete(USER,selection ,  selectionArgs);

return 0;
    }

@Override
public String getType(Uri uri) {
return null;
    }

@Override
public Uri insert(Uri uri, ContentValues values) {
        Log.i(TAG, "AAAAAAAAAAAAAAAAA");
        SQLiteDatabase db = helper.getWritableDatabase();
        db.insert(USER, null, values);

return null;
    }

// 查找
@Override
public Cursor query(Uri uri, String[] projection, String selection,
            String[] selectionArgs, String sortOrder) {

        SQLiteDatabase db = helper.getReadableDatabase();
        db.query(USER, projection, selection, selectionArgs, null, null, sortOrder);
return null;
    }

// 修改
@Override
public int update(Uri uri, ContentValues values, String selection,
            String[] selectionArgs) {

        SQLiteDatabase db = helper.getWritableDatabase();
        db.update(USER, values, selection, selectionArgs);
return 0;
    }

/**
 * 添加的方法
 * 使用数组添加多个对象
 */
@Override
public int bulkInsert(Uri uri, ContentValues[] values) {
        SQLiteDatabase db = helper.getWritableDatabase();
for (int i = 0; i < values.length; i++) {
            db.insert(USER, null, values[i]);
        }

return 0;
    }

}