Well this doesnt work yet, and is likely not the correct way, this needs more thought put into it, probably a complete rewrite is advisable because bringing this into a shape where it could have multiple Providers is hard

internal/database/chapter.go

@@ -0,0 +1,11 @@
+package database
+
+type Chapter struct {
+	Id                 int
+	Manga              *Manga
+	InternalIdentifier string
+	Url                string
+	Name               string
+	Number             int
+	TimeStampUnix      int64
+}

internal/database/createDb.sql

@@ -1,16 +1,27 @@
-create table if not exists Manga (
-    ID integer not null primary key,
-    Title text,
-    TimeStampUnixEpoch int,
-    Thumbnail blob
+drop table if exists Chapter;
+drop table if exists Manga;
+
+create table if not exists Manga
+(
+    ID                 integer not null primary key autoincrement,
+
+    Provider           integer not null,
+
+    Rating             integer,
+    Title              text,
+    TimeStampUnixEpoch integer,
+    Thumbnail          blob
 );
 
-create table if not exists Chapter (
-    ID integer not null primary key,
-    MangaID integer not null,
-    Url text not null,
-    Name text null,
-    Number int not null,
-    TimeStampUnixEpoch int,
-    foreign key(MangaID) references Manga(ID)
-);
+create table if not exists Chapter
+(
+    ID                 integer not null primary key autoincrement,
+    MangaID            integer not null,
+
+    InternalIdentifier text not null,
+    Url                text    not null,
+    Name               text    null,
+    Number             integer not null,
+    TimeStampUnixEpoch integer,
+    foreign key (MangaID) references Manga (ID)
+);

internal/database/database.go

@@ -5,30 +5,12 @@ import (
 	"database/sql"
 	_ "embed"
 	"fmt"
+	"mangaGetter/internal/provider"
 	"sync"
 
 	_ "github.com/mattn/go-sqlite3"
 )
 
-type Manga struct {
-	Id            int
-	Title         string
-	TimeStampUnix int64
-	Thumbnail     *bytes.Buffer
-
-	// Not in DB
-	LatestChapter *Chapter
-}
-
-type Chapter struct {
-	Id            int
-	Manga         *Manga
-	Url           string
-	Name          string
-	Number        int
-	TimeStampUnix int64
-}
-
 type Manager struct {
 	ConnectionString string
 	db               *sql.DB
@@ -183,7 +165,7 @@ func (dbMgr *Manager) load() error {
 		dbMgr.Rw.Unlock()
 	}()
 
-	rows, err := db.Query("SELECT * FROM Manga")
+	rows, err := db.Query("SELECT ID, Provider, Title, TimeStampUnixEpoch, Thumbnail, Rating FROM Manga")
 	if err != nil {
 		return err
 	}
@@ -191,14 +173,16 @@ func (dbMgr *Manager) load() error {
 	for rows.Next() {
 		manga := Manga{}
 		var thumbnail []byte
-		if err = rows.Scan(&manga.Id, &manga.Title, &manga.TimeStampUnix, &thumbnail); err != nil {
+		var providerId int
+		if err = rows.Scan(&manga.Id, &providerId, &manga.Title, &manga.TimeStampUnix, &thumbnail, &manga.Rating); err != nil {
 			return err
 		}
 		manga.Thumbnail = bytes.NewBuffer(thumbnail)
+		manga.Provider = provider.GetProviderByType(provider.ProviderType(providerId))
 		dbMgr.Mangas[manga.Id] = &manga
 	}
 
-	rows, err = db.Query("SELECT * FROM Chapter")
+	rows, err = db.Query("SELECT ID, MangaID, Url, Name, Number, TimeStampUnixEpoch, InternalIdentifier FROM Chapter")
 	if err != nil {
 		return err
 	}
@@ -206,7 +190,7 @@ func (dbMgr *Manager) load() error {
 	for rows.Next() {
 		chapter := Chapter{}
 		var mangaID int
-		if err = rows.Scan(&chapter.Id, &mangaID, &chapter.Url, &chapter.Name, &chapter.Number, &chapter.TimeStampUnix); err != nil {
+		if err = rows.Scan(&chapter.Id, &mangaID, &chapter.Url, &chapter.Name, &chapter.Number, &chapter.TimeStampUnix, &chapter.InternalIdentifier); err != nil {
 			return err
 		}
 

internal/database/manga.go

@@ -0,0 +1,18 @@
+package database
+
+import (
+	"bytes"
+	"mangaGetter/internal/provider"
+)
+
+type Manga struct {
+	Id            int
+	Provider      provider.Provider
+	Rating        int
+	Title         string
+	TimeStampUnix int64
+	Thumbnail     *bytes.Buffer
+
+	// Not in DB
+	LatestChapter *Chapter
+}