登录注册使用数据库

首先创建数据库

public class SQLiteHelper extends SQLiteOpenHelper {    public SQLiteHelper(Context context, String name, SQLiteDatabase.CursorFactory factory, int version) {        super(context, name, factory, version);    }    @Override    public void onCreate(SQLiteDatabase db) {        String sql = "create table if not exists user(_id integer primary key autoincrement,uname varchar(20),upass varchar(20))";        db.execSQL(sql);//        db.execSQL("insert into user (uname,upass) values('15039969751','123456')");    }    @Override    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {    }}

创建一个数据库 运行

登录

SQLiteHelper helper;private SQLiteDatabase read;private SQLiteDatabase write;

helper=new SQLiteHelper(getActivity(),"user",null,1);read=helper.getReadableDatabase();write = helper.getWritableDatabase();

连接数据库 根据需求判断 使用读取还是写入

String sql="select * from user where uname=? and upass=?";Cursor query = read.rawQuery(sql,new String[]{username,password});if(query.moveToNext()==true){    Toast.makeText(getActivity(),"登陆成功",Toast.LENGTH_SHORT).show();    Intent tomain=new Intent(getActivity(), MainActivity.class);    getActivity().startActivity(tomain);}else{    Toast.makeText(getActivity(),"登陆失败，请注册",Toast.LENGTH_SHORT).show();}

查询数据库 根据返回值输入输出

注册

String name = rogUsername.getText().toString();String pass = rogPassword.getText().toString();String pass_repeat=rogPasswordRepeat.getText().toString();if(pass.equals(pass_repeat)){    String sql = "insert into user(uname,upass) values(?,?)";    write.execSQL(sql,new String[]{name,pass});    Toast.makeText(getActivity(),"注册成功",Toast.LENGTH_SHORT).show();}else{    Toast.makeText(getActivity(),"两次密码不一致,请重新注册",Toast.LENGTH_SHORT).show();}
注册成功输入数据库的值