SQLITE ANDROID Studio。如何判断用户是管理员还是用户？[复制]

Question

The super admin can only enter username and password as well as user and admin. The super admin can crude accounts, while admin can also do the same except delete. and the user can only login. 

package com.example.myapplication;

import android.annotation.SuppressLint;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

public class myDbAdapter {

    myDbHelper myhelper;
    public myDbAdapter(Context context) {
        myhelper = new myDbHelper(context);
    }

    static class myDbHelper extends SQLiteOpenHelper {
        private static final String DATABASE_NAME = "LoginSystem_db";
        private static final String TABLE_NAME = "LoginSystem_tb";
        private static final int DATABASE_Version = 1;
        private static final String USERID = "Id";
        private static final String USERNAME = "Username";
        private static final String USERPASSWORD = "Password";
        private static final String ACCOUNTTYPE = "User_type";
        private static final String CREATE_TABLE = "CREATE TABLE " + TABLE_NAME +
    " (" + USERID + " INTEGER PRIMARY KEY AUTOINCREMENT, " + USERNAME + " VARCHAR(255) UNIQUE ," + USERPASSWORD + " VARCHAR(225)," + ACCOUNTTYPE + " VARCHAR(225));";
private static final String DROP_TABLE = "DROP TABLE IF EXISTS " + TABLE_NAME;
private Context context;

        public myDbHelper(Context context) {
            super(context, DATABASE_NAME, null, DATABASE_Version);
            this.context = context;
        }

        public void onCreate(SQLiteDatabase db) {
            try {

                db.execSQL(CREATE_TABLE);
            } catch (Exception e) {
                Message.message(context, "" + e);
            }
        }

  

  @Override
        public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
            db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
            onCreate(db);
        }
    }


    public Boolean insertData(String name, String pass, String type) {
        SQLiteDatabase db = myhelper.getWritableDatabase();
        ContentValues contentValues = new ContentValues();
        contentValues.put(myDbHelper.USERNAME, name);
        contentValues.put(myDbHelper.USERPASSWORD, pass);
        contentValues.put(myDbHelper.ACCOUNTTYPE, type);
        long dData = db.insert(myDbHelper.TABLE_NAME, null, contentValues);
        if (dData == -1)
            return false;
        else
            return true;



    }

    public String getData() {

        SQLiteDatabase db = myhelper.getWritableDatabase();
        String[] columns = {
            myDbHelper.USERID,
            myDbHelper.USERNAME,
            myDbHelper.USERPASSWORD,
            myDbHelper.ACCOUNTTYPE
        };
        Cursor cursor = db.query(myDbHelper.TABLE_NAME, columns, null, null, null, null, null);
        StringBuffer buffer = new StringBuffer();
        while (cursor.moveToNext()) {
            @SuppressLint("Range") int cid = cursor.getInt(cursor.getColumnIndex(myDbHelper.USERID));
            @SuppressLint("Range") String username = cursor.getString(cursor.getColumnIndex(myDbHelper.USERNAME));
            @SuppressLint("Range") String password = cursor.getString(cursor.getColumnIndex(myDbHelper.USERPASSWORD));
            @SuppressLint("Range") String usertype = cursor.getString(cursor.getColumnIndex(myDbHelper.ACCOUNTTYPE));
            buffer.append(cid + "   " + username + "   " + password + "  " + usertype + " \n");
        }
        return buffer.toString();
    }
    public Boolean checkusername(String username) {
        SQLiteDatabase MyDB = myhelper.getWritableDatabase();
        Cursor cursor = MyDB.rawQuery("Select * from LoginSystem_tb where USERNAME = ?", new String[] {
            username
        });
        if (cursor.getCount() > 0)
            return true;
        else
            return false;
    }
    public Boolean checkusernamepassword(String username, String password) {
        SQLiteDatabase MyDB = myhelper.getWritableDatabase();
        Cursor cursor = MyDB.rawQuery("Select * from LoginSystem_tb where USERNAME = ? and PASSWORD = ?", new String[] {
            username,
            password
        });
        if (cursor.getCount() > 0)
            return true;
        else
            return false;
    }
    public Boolean checkuserType() {
        SQLiteDatabase MyDB = myhelper.getWritableDatabase();
        Cursor cursor = MyDB.rawQuery("Select * from LoginSystem_tb where USERTYPE= 'Admin'", new String[] {});
        if (cursor.getCount() > 0)
            return true;
        else
            return false;
    }

超级管理员、管理员和用户。超级管理员可以为用户和管理员创建用户名、密码和用户类型（单选按钮）。我想做的是，当我输入登录用户名和密码时，系统将自动知道该用户是管理员或用户。如何获取已插入sql db的单选按钮的数据

}

如何获取已经存储在sql db中的用户类型（单选按钮）的数据。然后将其放入if条件。如果我的问题是正确的，但我想要的是区分用户和管理员。谢谢！输出

MainActivity.java

 buttonLogin.setOnClickListener(new View.OnClickListener() {
 @Override
 public void onClick(View view) {
     String usernameLog = usernameOutside.getText().toString();
     String passwordLog = passwordOutside.getText().toString();

     if ((usernameLog.equals("admin")) && (passwordLog.equals("admin"))) {
         Intent intent = new Intent(MainActivity.this,
             MainActivity2.class);
         startActivity(intent);
     } else {

         Boolean checkUserPass = mynewdbAdapter.checkusernamepassword(usernameLog, passwordLog);

         if (checkUserPass) { //check if existing
             if ( //check if this is user or admin) {
                 Toast.makeText(MainActivity.this, "Login Successful.", Toast.LENGTH_SHORT).show();
             }
             else {
                 Toast.makeText(MainActivity.this, "Invalid.", Toast.LENGTH_SHORT).show();
             }

         } else {
                 Toast.makeText(MainActivity.this, "Account doesn't exist.", Toast.LENGTH_SHORT).show();
             }
         }
     }
 });


 How can I get the data which is the user type(radio button) that is already stored in the sql db. Then put it in if conditions. Idk if my questions are right but What I want is differentiate user and admin. Thank you!

输出

里面输出

Answer 1

我认为您需要修复getUserType（）函数

你可以：

1. 将返回类型更改为包含所有管理员用户的列表。然后，您可以将用户的用户名与管理员列表进行比较
2. 更好的方法是保持函数为布尔值，但要传递用户id，请检查帐户类型是否为ADMIN，否则返回True或False。然后可以从主活动中调用该函数，类似于调用checkUsernamePassword函数

我希望这对你有帮助

从长远来看，函数可以如下所示：

public Boolean checkuserType(string input_name) {

    SQLiteDatabase MyDB = myhelper.getWritableDatabase();
    Cursor cursor = MyDB.rawQuery("Select USERTYPE from LoginSystem_tb where USERNAME= input_name", new String[] {});
    if (cursor.fetchOne().equals("ADMIN"))
        return true;

    else
        return false;
}