C ++: general interface design for the database

Question

I have a class that is used to create a database connection:

class DBHandler
{
public:
    DBHandler();
   ~DBHandler();

    int connect();
    int execQuery( string query);
    string getField( int row, int col);
};

Now there is another class that is used to get some information from the database,

class DBManager
{
public:
    DBManager();
   ~DBManager();

   //Approach 1
   string getUsername()
   {
      //create a query here and use     object of DBHandler class to execute it.
   }

   //Approach 2
   string getUsername (struct     QueryDetails& qDetails)
   {
      //create query using fields of structure and execute the query using DBHandler class.
   }
 };

Now here is the problem:

1) to which I must follow:

• A) If I use approach 1, then I need to request a hard code.
• B) If I use approach 2, I need to populate the structure every time before calling the getUsername function.

2) Is there a better solution than two that would be common?

PS: Structure Definition

struct QueryDetails
{
    string tableName;
    vector<string> colList;
 ...
};

Answer 1

Your question is very broad, and the elements that you give do not allow you to offer you an objective, best answer.

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