Is there a way to stash an entire SQLite query result into a string?

Question

I want to - just for "Proof of Concept's sake" - display an entire query result set as a string. And I want the table queried to be a variable.

How can it be done? I've got the following start:

public String[] getAllRecordsFrom(String tblName) {
    String query = "Select * FROM " + tblName;
    String[] results = null;
    SQLiteDatabase db = this.getWritableDatabase();
    Cursor cursor = db != null ? db.rawQuery(query, null) : null;
    if (cursor == null) return results;
    while (cursor.moveToFirst()) {
        results. <== now what?
    }
    cursor.close();

    if (db != null) {
        db.close();
    }
    return results;
}

...but don't know how to proceed from the "<== now what?" part.

UPDATE

Based on Greg's ideas/code, I'm going to try this:

// Generic * query
public StringBuilder getAllRecordsFrom(String tblName) {
    String query = "Select * FROM " + tblName;
    StringBuilder results = new StringBuilder();
    SQLiteDatabase db = this.getWritableDatabase();
    Cursor cursor = db != null ? db.rawQuery(query, null) : null;
    if (cursor == null) return results;
    int colCount = cursor.getColumnCount();
    cursor.moveToFirst();
    while (true) {
        for (int i = 0; i < colCount; i++) {
            results.append(cursor.getString(i).toString());
            // if the above (getting all data types as string) doesn't work, see if this (pseudocode) will: Type t = results.append(cursor.getType(i); if t == int then getint(i), else if t == string then getString(i), &c.
        }
        if (cursor.isLast()) break;
        cursor.moveToNext();
    }
    cursor.close();

    if (db != null) {
        db.close();
    }
    return results;
}

UPDATE 2

Okay, that worked, along with this:

private class ShowLocalDataTask extends AsyncTask<String, String, String> {

    @Override
    protected String doInBackground(String... strings) {
        String tbl = strings[0];
        SQLiteOpenHelperHHS sqliteHHS = new SQLiteOpenHelperHHS(SQLiteActivity.this, null);
        StringBuilder sb = sqliteHHS.getAllRecordsFrom(tbl);
        return sb.toString();
    }

    @Override
    protected void onPostExecute(String result) {
        EditText etmultiline = (EditText) findViewById(R.id.editTextMultiline);
        if (result == null) return;
        etmultiline.setText(result);
        Log.i("QueryResults", result);
    }
}

Note: If the ".toString() hadn't have worked, presumably I could have used "cursor.getType(i)" The return vals of getType are: 0 == null, 1 == int, 2 == float (REAL), 3 == String, 4 == BLOb

UPDATE 3

This is a little more "elegant," I think (getting the columns as their types):

public StringBuilder getAllRecordsFrom(String tblName) {
    final int NULLVAL = 0;
    final int INTVAL = 1;
    final int FLOATVAL = 2;
    final int STRINGVAL = 3;
    final int BLOBVAL = 4;

    String query = "Select * FROM " + tblName;
    StringBuilder results = new StringBuilder();
    SQLiteDatabase db = this.getWritableDatabase();
    Cursor cursor = db != null ? db.rawQuery(query, null) : null;
    if (cursor == null) return results;
    int colCount = cursor.getColumnCount();
    cursor.moveToFirst();

    int typeVal;
    while (true) {
        for (int i = 0; i < colCount; i++) {
            typeVal = cursor.getType(i);
            switch (typeVal) {
                case NULLVAL:
                    // nuttin', honey
                    break;
                case INTVAL:
                    results.append(cursor.getInt(i)).toString();
                    break;
                case FLOATVAL:
                    results.append(cursor.getFloat(i)).toString();
                    break;
                case STRINGVAL:
                    results.append(cursor.getString(i));
                    break;
                case BLOBVAL:
                    //results.append(cursor.getBlob(i)).toString();
                    // Probably better off doing it this way:
                    results.append("BLOb" + String.valueOf(i));
                    break;
            }
        }
        if (cursor.isLast()) break;
        cursor.moveToNext();
    }
    cursor.close();

    if (db != null) {
        db.close();
    }
    return results;
}

Answer 1

You might do better to use the StringBuilder class like this (note this gives you one huge string, not an array of strings; if you want an array where each row of the cursor is it's own element, then declare results as an ArrayList, replace results.append with results.add and return results.toArray().

public String getAllRecordsFrom(String tblName) {
    String query = "Select * FROM " + tblName;
    StringBuilder results = new StringBuilder();
    SQLiteDatabase db = this.getWritableDatabase();
    Cursor cursor = db != null ? db.rawQuery(query, null) : null;
    if (cursor == null) { return null }

    cursor.moveToFirst();
    while (true) {
        results.append(cursor.getString(0));  // this assumes only one column in the results
        if (cursor.isLast()) break;
        cursor.moveToNext();
    }
    cursor.close();

    if (db != null) {
        db.close();
    }
    return results.toString();
}