Dependencies between models in flutter - sqlite

Question

Help me please. There is a database that contains several tables:
1) The names of the authors of poems.
2) The names of poems.
One table is linked to another using an ID (in the table with the names of the poems there is a column with the author ID).
It is necessary that by clicking on the author poems of this author open. I can’t figure out how to make this connection.
Authors.dart (The models of authors)
Authors authorsFromJson(String str) {
final jsonData = json.decode(str);
return Authors.fromMap(jsonData);
}
String authorsToJson(Authors data) {
final dyn = data.toMap();
return json.encode(dyn);
}
class Authors {
int id;
String name;
int count;
Authors({
this.id,
this.name,
this.count,
});
factory Authors.fromMap(Map<String, dynamic> json) => new Authors(
id: json["c_id"],
name: json["c_title"],
count: json["c_i_count"],
);
Map<String, dynamic> toMap() => {
"c_id": id,
"c_title": name,
"c_i_count": count,
};
}
PoemsTitle.dart (The models of PoemsTitle)
PoemsTitle poemsTitleFromJson(String str) {
final jsonData = json.decode(str);
return PoemsTitle.fromMap(jsonData);
}
String poemsTitleToJson(PoemsTitle data) {
final dyn = data.toMap();
return json.encode(dyn);
}
class PoemsTitle {
int id;
String title;
int authorsId;
PoemsTitle({
this.id,
this.title,
this.authorsId,
});
factory PoemsTitle.fromMap(Map<String, dynamic> json) => new PoemsTitle(
id: json["ii_i_id"],
title: json["ii_i_title"],
authorsId: json["ii_col_int_2"],
);
Map<String, dynamic> toMap() => {
"ii_i_id": id,
"ii_i_title": title,
"ii_col_int_2": authorsId,
};
}
Column c_title from the category table must be associated with column ii_col_int_2 from the items_info table.
Methods from DBProvider:
...Future<List<Authors>> getAllAuthors() async {
final db = await database;
var res = await db.query('category');
List<Authors> list = res.map((c) => Authors.fromMap(c)).toList();
return list;
}
Future<List<PoemsTitle>> getAllPoemsTitle() async {
final db = await database;
var res = await db.query('items_info');
List<PoemsTitle> list = res.map((c) => PoemsTitle.fromMap(c)).toList();
return list;
}
And pages from FutureBuilder and ListView.builder:
This is a widget where poems are displayed after clicking on the corresponding author:
class FavoriteTab extends StatelessWidget {
int authorId;
int count;
FavoriteTab({this.authorId, this.count});
#override
Widget build(BuildContext context) {
return Scaffold(
body: Padding(
padding: const EdgeInsets.only(left: 10, right: 10, bottom: 10),
child: Container(
padding: EdgeInsets.all(5),
decoration: BoxDecoration(
color: Theme.of(context).accentColor,
borderRadius: BorderRadius.all(Radius.circular(30))
),
child: FutureBuilder<List<PoemsTitle>>(
future: DBProvider.db.getAllPoemsTitle(),
builder: (context, snapshot) {
switch (snapshot.connectionState) {
case ConnectionState.waiting:
return Center(
child: CircularProgressIndicator(),
);
case ConnectionState.done:
{
if (snapshot.hasError) {
return Center(
child: Text(snapshot.error.toString()),
);
} else if (snapshot.hasData) {
return Scrollbar(
child: ListView.builder(
physics: BouncingScrollPhysics(),
itemCount: this.count,
itemBuilder: (context, index) {
PoemsTitle item = snapshot.data[index];
return ListTile(
title: Text(item.title),
leading: Icon(Icons.receipt),
trailing: Icon(Icons.favorite, color: Colors.red, size: 34),
onTap: () {
},
);
},
)
);
}
return Center(
child: Text('No Data')
);
}
default:
return Container();
}
},
)
),
),
);
}
}
And this is the Widget with the authors:
class MainTab extends StatefulWidget {
#override
_MainTabState createState() => _MainTabState();
}
class _MainTabState extends State<MainTab> {
#override
Widget build(BuildContext context) {
return Padding(
padding: const EdgeInsets.only(left: 10, right: 10, bottom: 10),
child: Container(
padding: EdgeInsets.all(5),
decoration: BoxDecoration(
color: Theme.of(context).accentColor,
borderRadius: BorderRadius.all(Radius.circular(30))
),
child: FutureBuilder<List<Authors>>(
future: DBProvider.db.getAllAuthors(),
builder: (context, snapshot) {
switch (snapshot.connectionState) {
case ConnectionState.waiting:
return Center(
child: CircularProgressIndicator(),
);
case ConnectionState.done:
{
if (snapshot.hasError) {
return Center(
child: Text(snapshot.error.toString()),
);
} else if (snapshot.hasData) {
return Scrollbar(
child: ListView.builder(
physics: BouncingScrollPhysics(),
itemCount: snapshot.data.length,
itemBuilder: (context, index) {
Authors item = snapshot.data[index];
return ListTile(
title: Text(item.name),
leading: Icon(Icons.folder),
trailing: Text(item.count.toString()),
onTap: () {
Navigator.push(
context,
MaterialPageRoute(
builder: (context) => FavoriteTab(authorId: item.id, count: item.count)
)
);
},
);
},
)
);
}
return Center(
child: Text('No Data')
);
}
default:
return Container();
}
},
)
),
);
}
}

Answer 1

I think the problem is on this line, in the FavoriteTab widget:
future: DBProvider.db.getAllPoemsTitle(),
Here you ALWAYS query all poems. The right thing is to create a method like getPoemOfAuthor(int authorID) in DBProvider, and since you pass the authorId when you open your FavoriteTab, in the FutureBuilder you must call:
future: DBProvider.db.getPoemOfAuthor(authorId),
Hope this will help!