Commit 551aca4

@@ -0,0 +1,53 @@
+import 'package:blood_pressure_app/model/storage/db/config_db.dart';
+import 'package:blood_pressure_app/model/storage/settings_store.dart';
+import 'package:sqflite/sqflite.dart';
+
+class ConfigDao {
+  ConfigDao(this._configDB);
+  
+  final ConfigDB _configDB;
+
+  /// Loads the profiles [Settings] object from the database.
+  ///
+  /// If any errors occur or the object is not present, a default one will be created. Changes in the object
+  /// will save to the database automatically (a listener gets attached).
+  Future<Settings> loadSettings(int profileID) async {
+    final dbEntry = await _configDB.database.query(
+      ConfigDB.settingsTable,
+      columns: ['settings_json'],
+      where: 'profile_id = ?',
+      whereArgs: [profileID]
+    );
+
+    late final Settings settings;
+    if (dbEntry.isEmpty) {
+      settings = Settings();
+    } else {
+      assert(dbEntry.length == 1, 'The profile_id should be unique.');
+      final settingsJson = dbEntry.first['settings_json'];
+      if (settingsJson == null) {
+        settings = Settings();
+      } else {
+        settings = Settings.fromJson(settingsJson.toString());
+      }
+    }
+    settings.addListener(() {
+      _updateSettings(profileID, settings);
+    });
+    return settings;
+  }
+
+  /// Update settings for a profile in the database.
+  ///
+  /// Adds an entry if necessary.
+  Future<void> _updateSettings(int profileID, Settings settings) async {
+    await _configDB.database.insert(
+      ConfigDB.settingsTable,
+      {
+        'profile_id': profileID,
+        'settings_json': settings.toJson()
+      },
+      conflictAlgorithm: ConflictAlgorithm.replace
+    );
+  }
+}
\ No newline at end of file

@@ -12,6 +12,23 @@ import 'package:sqflite/sqflite.dart';
 /// internalColumnName STRING PRIMARY KEY, columnTitle STRING, formatPattern STRING
 class ConfigDB {
   ConfigDB._create();
+  
+  /// Name of the settings table.
+  ///
+  /// It is used to store json representations of [Settings] objects.
+  ///
+  /// Format:
+  /// `CREATE TABLE settings(profile_id: INTEGER PRIMARY KEY, settings_json: STRING)`
+  static const String settingsTable = 'settings';
+  // instead of just changing this string when changing the format, _onDBUpgrade should be used.
+  static const String _settingsTableCreationString =
+      'CREATE TABLE settings(profile_id: INTEGER PRIMARY KEY, settings_json: STRING)';
+
+  /// Name of the exportStrings table. It is used to store formats used in the [ExportConfigurationModel].
+  static const String exportStrings = 'exportStrings';
+  // instead of just changing this string when changing the format, _onDBUpgrade should be used.
+  static const String _exportStringsTableCreationString =
+      'CREATE TABLE exportStrings(internalColumnName STRING PRIMARY KEY, columnTitle STRING, formatPattern STRING)';
 
   late final Database _database;
 
@@ -32,16 +49,15 @@ class ConfigDB {
   }
 
   FutureOr<void> _onDBCreate(Database db, int version) {
-    db.execute(
-        'CREATE TABLE exportStrings(internalColumnName STRING PRIMARY KEY, columnTitle STRING, formatPattern STRING)');
-    db.execute('CREATE TABLE settings(profile_id: INTEGER PRIMARY KEY, settings_json: STRING)');
+    db.execute(_exportStringsTableCreationString);
+    db.execute(_settingsTableCreationString);
   }
 
   FutureOr<void> _onDBUpgrade(Database db, int oldVersion, int newVersion) async {
     // When adding more versions the upgrade procedure proposed in https://stackoverflow.com/a/75153875/21489239
     // might be useful, to avoid duplicated code. Currently this would only lead to complexity, without benefits.
     if (oldVersion == 1 && newVersion == 2) {
-      db.execute('CREATE TABLE settings(profile_id: INTEGER PRIMARY KEY, settings_json: STRING)');
+      db.execute(_settingsTableCreationString);
       db.database.setVersion(2);
     } else {
       assert(false, 'Unexpected version upgrade from $oldVersion to $newVersion.');

@@ -17,7 +17,7 @@ import 'package:flutter/material.dart';
 class Settings extends ChangeNotifier {
   /// Creates a settings object with the default values.
   ///
-  /// Should only be called directly by tests and from factory methods.
+  /// When the values should be set consider using the factory methods.
   Settings({
     MaterialColor? accentColor,
     MaterialColor? sysColor,