Question 76320 in Flutter Question posted in
The official Flutter documentation can be found here.

How can I use List<String> in a for loop to both generate column name AND value of that column? – Flutter

I have a Flutter app that gets data from an SQLite database. That database has a table with a huge number of columns, so I’ve written a function that puts those column names into a list.

Therefore, columnsList contains list of the columns in my database table.

How can I use columnsList to BOTH display the name of the column AND the VALUE of that column in a for loop?

Pseudocode

List<String> columnsList = [];

columnsList = ['RecordId', 'FirstName', 'MiddleName', 'LastName', 'Suffix', 'StreetNumber', 'StreetName'];

fetchRecord(1); // Inside initState() - returns values shown in example output

for (var i in columnsList) ...[
                    Text("$i: <<<VALUE OF i>>>"),   // Here's where I need help
                  ],

fetchRecord

Fetch Record looks something like this with a huge list of variables that I’d like to replace with the list.

//--- Fetch Record ---
  bool isLoading = true;
  List<Map<String, dynamic>> myRecord = [];
  void fetchRecord(int recordId) async {
    final data = await SQLiteMethods.getRecord(recordId);
    setState(() {
      myRecord = data;
      firstName = myRecord[0]["FirstName"].toString() ?? '';
      middleName = myRecord[0]["MiddleName"].toString() ?? '';
      lastName = myRecord[0]["LastName"].toString() ?? '';
      suffix = myRecord[0]["Suffix"].toString() ?? '';
      streetNumber = myRecord[0]["StreetNumber"].toString() ?? '';
      streetName = myRecord[0]["StreetName"].toString() ?? '';
      isLoading = false;
    });
  }

Example Output

RecordId: 1
FirstName: Bob
MiddleName: E
LastName: Jones
Suffix: Mr
StreetNumber: 123
StreetName: Main St

Thanks for your help!

Tags:

2

Answers


  1. 0

    I tried to display your items from SQLiteMethods.getRecord with recordId from Widget.

    I hope this helps.

    class YourWidget extends StatefulWidget {
  const YourWidget({Key? key, required this.recordId}) : super(key: key);
  final int recordId;

  @override
  State<YourWidget> createState() => _YourWidgetState();
}

class _YourWidgetState extends State<YourWidget> {
  List<Map<String, dynamic>> myRecord = [];
  final List<String> columnsList = [
    'RecordId',
    'FirstName',
    'MiddleName',
    'LastName',
    'Suffix',
    'StreetNumber',
    'StreetName'
  ];
  bool isLoading = false;

  @override
  void initState() {
    super.initState();
    fetRecord(widget.recordId);
  }

  Future<void> fetRecord(int recordId) async {
    isLoading = true;
    myRecord = await SQLiteMethods.getRecord(recordId);
    isLoading = false;
    setState(() {});
  }

  @override
  Widget build(BuildContext context) {
    if (isLoading) {
      return const Center(
        child: CircularProgressIndicator(),
      );
    }
    return Column(children: [
      for (final record in myRecord)
        Container(
          color: Colors.black12,
          padding: const EdgeInsets.all(10),
          child: Column(
            children: [for (final key in columnsList) Text('$key: ${record[key]}')],
          ),
        )
    ]);
  }

    If you are getting Map from SQLiteMethods.getRecord, then you should do two changes,

    1. List<Map<String, dynamic>> myRecord = []; to Map<String, dynamic> myRecord = {};.
    2. Remove the higher level Column and lower level should be for (final key in columnsList) Text('$key: ${myRecord[key]}')
    Login or Signup to reply.
  2. 0

    use this:

    Column(children: [for (var i in columnsList) Text("twxt: ${i}")])
    Login or Signup to reply.
Please signup or login to give your own answer.

Back To Top
Search