如何验证用户使用SQLite数据库中的凭据输入的凭据

Question

现在我的工作Sample login application中,user能够login与他们username并password按下login button.如果user是新的,那么他/她也可以通过选择username和注册password.这registration部分应用程序工作正常.

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我的实际问题是:如何将输入的用户credentials与存储的用户进行比较database.

我使用SELECT查询来选择用户名和密码

public void ValidateLogin(String un, String pwd)
     {
        SELECT_FROM = "SELECT u_name, u_pwd FROM" + table_name + "WHERE u_name == " + un + "AND u_pwd ==" + pwd;
        db.execSQL(SELECT_FROM);
     }

其中,username(un)与password(pwd)来自另一个java file login.java.

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现在请告诉我在成功登录后如何成功转换到viewprofile页面？

Answer 1

You can use `cursor` with `rawquery` to validate username and password in one boolean type of method

    public boolean ValidateLogin(String un, String pwd)
      {
        boolean chklogin=false;      
        c = db.rawQuery("SELECT u_name, u_pwd FROM " + table_name + " WHERE u_name = '"+ un + "' AND u_pwd ='"+ pwd + "'", null);

         if(c==null)
        {
            //set boolean var to false
               chklogin=false; 
           //message no such records 
         }

        else
         {
           //set boolean var to true 
               chklogin=true;
               c.moveToFirst(); 
         }

         return chklogin; //boolean var
}