運行原始的sqlite查詢

Question

我想運行這個查詢，但它只是不工作，我似乎無法找到它有什麼問題。

public boolean verifyUser(String name , String pword){ 
    boolean result = false; 
    SQLiteDatabase db = this.getReadableDatabase(); 
    try { 
    Cursor res = db.rawQuery("select * from user where username="+name+" and password="+pword+"", null); 

     int count = res.getCount(); 

     res.moveToFirst(); 
     if (count == 0) 
     { 
      result = false; 
     } 
     else{ 
     result = true; 
     } 
    } 
     catch (SQLiteException se) { 
      Log.e(getClass().getSimpleName(), "Could not log in"); 
     } 
     return result; 
     //return true; 
    } 

Answer 1

在SQL中，您需要將字符串文字放在'single quotes'中。更重要的是，使用參數：

Cursor res = db.rawQuery("select * from user where username=? and password=?", 
    new String[] { name, pword }); 

Answer 2

複製並粘貼以下查詢

select * from user where username='"+name+"' and password='"+pword+"'" 

其實你缺少單引號

Answer 3

經過這一點，它的編輯你的代碼。

public boolean verifyUser(String name , String pword){ 
    boolean result = false; 
    SQLiteDatabase db = this.getReadableDatabase(); 
    try { 
    Cursor res = db.rawQuery("select * from user where username='"+name+"' and password='"+pword+"'", null); 

     int count = res.getCount(); 

     //res.moveToFirst(); //Remove this line (It may be crashing because of this line.) 
     if (count == 0) 
     { 
      result = false; 
     } 
     else{ 
     res.moveToFirst(); 
     result = true; 
     } 
    } 
     catch (SQLiteException se) { 
      Log.e(getClass().getSimpleName(), "Could not log in"); 
     } 
     return result; 
     //return true; 
    }