How to select with sharedpreferences keys in mysql database (or json) in flutter to list favorite records?

Question

I would like to save the sharedpreferences keys on my smartphone. The keys are table id's (autoincrements) from a table. Now i would like to show these favorite records in a new tab.

How can i select with these keys in my database table? Or is it possible to compare them with all records in a json dataset what i select at the beginning to show all records from the table?

At the moment i'm saving the keys in Strings. And then showing them in a listview.

  Future<void> _save() async {
    SharedPreferences prefs = await SharedPreferences.getInstance();
    final key = '${widget.id}';
    final value = '${widget.id}';
    prefs.setString(key, value);
  }


  Future<List<Widget>> getAllPrefs() async {
    SharedPreferences prefs = await SharedPreferences.getInstance();
    //final SharedPreferences prefs = await PrefStore().prefs;
    return prefs
        .getKeys()
        .map<Widget>((key) => ListTile(
      title: Text(key),
      subtitle: Text(prefs.get(key).toString()),
    ))
        .toList(growable: false);
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: FutureBuilder<List<Widget>>(
          future: getAllPrefs(),
          builder: (context, snapshot) {
            if (!snapshot.hasData) return Container();
            return ListView(
              children: snapshot.data,
            );
          }),
    );
  }

Thank you very much.

Answer 1

I have got a good idea which works fine, see below. But if you have a better solution please post it too.

I used only one future for getInstance and SQL-Select.

// get the keys, convert to string, change {1,2,3} to (1,2,3) with strings/substring
    SharedPreferences prefs = await SharedPreferences.getInstance();
    String allkeys = prefs.getKeys().toString();
    keylist = '(' + allkeys.substring(1, allkeys.length - 1) + ')';

Then select with keylist as followed:

select * from table where table.id in $keylist
// means: ... where table.id in (1,2,3)

If you need more code, please comment, thx