SQL查詢不從數據庫中讀取數據

所以我有兩個遊標從數據庫讀取數據並將數據寫入字符串，但即使數據庫已存儲數據，遊標始終爲空。我使用SQLite管理器檢查數據庫是否包含存儲的數據。登錄貓說，日誌命名爲：「IF1」和「IF2執行這裏是我的代碼，我希望有人能找到什麼是錯的..SQL查詢不從數據庫中讀取數據

String var; 
final TextView t = (TextView) findViewById(R.id.textView2); 
final TextView t2 = (TextView) findViewById(R.id.textView3); 
Intent intent = getIntent(); 
var = intent.getStringExtra("datum"); 

SQLiteDatabase db = openOrCreateDatabase ("MyDB", MODE_PRIVATE, null); 

String q =" SELECT COALESCE (znak, '') as znak,COALESCE (sprava, '') as sprava, COALESCE(serija, '') as serija, COALESCE(podatak, '') as podatak, COALESCE(ponavljanja, '') as ponavljanja, vrijeme FROM tablica WHERE vrijeme LIKE '"+ var + "'" ; 
Cursor c = db.rawQuery(q, null);  

String xy = "SELECT vrijeme FROM tablica WHERE vrijeme LIKE '"+ var + "'"; 
Cursor dd = db.rawQuery(xy, null); 

if (dd.getCount() < 1) { 
    Log.d("LIST.DETAILS", "IF1"); 
    dd.close(); 
    db.close(); 
    Toast.makeText(NapredakActivity.this, "Empty!", Toast.LENGTH_SHORT).show(); 
    startActivity(new Intent(this, calendar.class)); 
} else { 
    String i = ""; 

    dd.moveToFirst(); 
    String st2 = dd.getString(dd.getColumnIndex("vrijeme")); 
    i = "Datum:" +"\t" + st2; 
    t2.setText(i); 
    dd.close(); 
} 

if (c.getCount() < 1) { 
    Log.d("LISTA.DETALJI", "IF2"); 
    c.close(); 
    db.close(); 
    Toast.makeText(NapredakActivity.this, "Empty!", Toast.LENGTH_SHORT).show(); 
    startActivity(new Intent(this, calendar.class)); 
} else { 
    String j = ""; 

    c.moveToFirst(); 
    do { 
     String cm55 = c.getString(c.getColumnIndex("sprava")); 
     String cm = c.getString(c.getColumnIndex("serija")); 
     String cm2 = c.getString(c.getColumnIndex("podatak")); 
     String cm3 = c.getString(c.getColumnIndex("ponavljanja")); 
     String cm_znak = c.getString(c.getColumnIndex("znak")); 

     j = j +cm55+ "\n" + cm + "\t" +cm2 +cm_znak + cm3 ; 
    } while (c.moveToNext()); 

    t.setText(j); 
    c.close(); 
    db.close(); 
}

來源

2012-07-04 user1414682

我相信你是從你在哪裏丟失的通配符條款：

"vrijeme LIKE '%"+ var + "%'"

否則：

"vrijeme LIKE '"+ var + "'"

是一樣的：

"vrijeme = '"+ var + "'"

另外我猜測英語不是你的第一語言，但你的變量名稱是非常神祕的。考慮使用更多的描述性名稱，它只是有助於您的代碼的可讀性。

來源

2012-07-04 18:38:55 Sam

謝謝你，那是問題..你一直很有幫助！ – user1414682

SQL查詢不從數據庫中讀取數據

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