检查记录在数据库中存在的android [英] Check if record exist in the database android

问题描述

我要检查，如果在SQLite数据库存在的记录，这是我迄今所做的。当我搜索一个已经存在的记录，从即时通讯中的EditText列表中获得价值。

  // $ C $从活动的C类

    公共View.OnClickListener searchStation =新View.OnClickListener（）{
    @覆盖
    公共无效的onClick（视图v）{
        arrayAdapterList =新的ArrayAdapter＆LT;字符串＆GT;（SearchAndReview.this，
                android.R.layout.simple_list_item_1，
                清单）;
        。字符串searchTextFinal = searchText.getText（）的toString（）;
        dbms.searchStation（searchTextFinal）;
        光标光标= dbms.searchStation（searchTextFinal）;



       list.add（searchTextFinal）;
        arrayAdapterList =新的ArrayAdapter＆LT;字符串＆GT;（SearchAndReview.this，
                android.R.layout.simple_list_item_1，清单）;
        listView.setAdapter（arrayAdapterList）;


    }
};
 

//从databasehelper类code

 公开光标searchStation（字符串名称）{
    SQLiteDatabase数据库= this.getWritableDatabase（）;
    字符串searchStationQuery =SELECT工作站名称评分WHERE的stationID ='+姓名+';
    光标C = database.rawQuery（searchStationQuery，NULL）;
    如果（C =空＆安培;！＆安培; c.moveToFirst（））{
    }
    返回℃;
}
 

解决方案

我在我的应用程序中使用这个code和它的作品perfact ...

  LoginActivity.java

DatabaseHelper dbHelper =新DatabaseHelper（getApplicationContext（））;
。字符串email_id = email.getText（）的toString（）;
布尔dbHelper.isExist（email_id）;

//如果记录存在，那么它将返回true，否则此方法返回false
 

 公共布尔ISEXIST（字符串email_id）{
        DB = this.getReadableDatabase（）;
        CUR = db.rawQuery（SELECT * FROM+ USER_TABLE +WHERE email_id ='+ email_id +'，NULL）;
        布尔存在=（cur.getCount（）大于0）;
        cur.close（）;
        db.close（）;
        返回存在;

    }
 

I want to check if records exist in the SQLite database, here's what I have done so far. when I search for a already existing records im getting value from EditText in list.

    //code from activity class

    public View.OnClickListener searchStation = new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        arrayAdapterList=new ArrayAdapter<String>(SearchAndReview.this,
                android.R.layout.simple_list_item_1,
                list);
        String searchTextFinal=searchText.getText().toString();
        dbms.searchStation(searchTextFinal);
        Cursor cursor= dbms.searchStation(searchTextFinal);



       list.add(searchTextFinal);
        arrayAdapterList= new ArrayAdapter<String>(SearchAndReview.this,
                android.R.layout.simple_list_item_1, list);
        listView.setAdapter(arrayAdapterList);


    }
};

// code from databasehelper class

   public Cursor searchStation(String name){
    SQLiteDatabase database = this.getWritableDatabase();
    String searchStationQuery = "SELECT stationName FROM review WHERE stationId='"+ name+"'";
    Cursor c =database.rawQuery(searchStationQuery,null);
    if (c != null && c.moveToFirst()) {
    }
    return c;
}

解决方案

I use this code in my application and it works perfact...

LoginActivity.java

DatabaseHelper dbHelper = new DatabaseHelper(getApplicationContext());
String email_id = email.getText().toString();
boolean dbHelper.isExist(email_id);

// if record is exist then it will return true otherwise this method returns false

 public boolean isExist(String email_id) {
        db = this.getReadableDatabase();
        cur = db.rawQuery("SELECT * FROM " + USER_TABLE + " WHERE email_id = '" + email_id + "'", null);
        boolean exist = (cur.getCount() > 0);
        cur.close();
        db.close();
        return exist;

    }

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