[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"academy-blogs-th-1-1-all-storing-chat-history-websocket-graphql-all--*":3,"academy-blog-translations-h9qo5h7vbko0hq3":104},{"data":4,"page":92,"perPage":92,"totalItems":92,"totalPages":92},[5],{"alt":6,"collectionId":7,"collectionName":8,"content":9,"cover_image":10,"cover_image_path":11,"created":12,"created_by":13,"expand":14,"id":99,"keywords":100,"locale":74,"published_at":101,"scheduled_at":13,"school_blog":96,"short_description":102,"status":94,"title":6,"updated":103,"updated_by":13,"slug":97,"views":98},"EP.35 การเก็บประวัติการแชทในระบบ WebSocket และ GraphQL Subscription","sclblg987654321","school_blog_translations","\u003Ch2>ทำไมต้องเก็บประวัติการแชท?\u003C\u002Fh2>\u003Cp>การเก็บประวัติการแชทช่วยให้ผู้ใช้สามารถดึงข้อมูลเก่า ดูประวัติข้อความ และใช้งานระบบแชทได้อย่างต่อเนื่อง ไม่ต้องสูญเสียข้อมูลเมื่อปิดแอปพลิเคชัน นอกจากนี้ยังช่วยให้ ระบบสามารถแสดงผลข้อความย้อนหลังได้ เช่น:\u003C\u002Fp>\u003Cul>\u003Cli>ดึงข้อความล่าสุดเมื่อผู้ใช้เข้าร่วมการสนทนา\u003C\u002Fli>\u003Cli>โหลดประวัติแชทย้อนหลัง\u003C\u002Fli>\u003Cli>บันทึกข้อความลงฐานข้อมูลเพื่อให้สามารถค้นหาได้ภายหลัง\u003C\u002Fli>\u003C\u002Ful>\u003Cp> \u003C\u002Fp>\u003Ch3>โครงสร้างของระบบเก็บประวัติการแชท\u003C\u002Fh3>\u003Col>\u003Cli>WebSocket Server - รับและส่งข้อความผ่าน WebSocket\u003C\u002Fli>\u003Cli>GraphQL API - จัดการการรับ-ส่งข้อความและเก็บข้อมูล\u003C\u002Fli>\u003Cli>Database (PostgreSQL \u002F MongoDB) - ใช้เก็บประวัติการแชท\u003C\u002Fli>\u003Cli>GraphQL Subscription - ส่งข้อความใหม่ให้ผู้ใช้แบบเรียลไทม์\u003C\u002Fli>\u003C\u002Fol>\u003Cp> \u003C\u002Fp>\u003Ch3>ติดตั้งไลบรารีที่จำเป็น\u003C\u002Fh3>\u003Cpre>\u003Ccode class=\"language-plaintext\">go get github.com\u002F99designs\u002Fgqlgen\ngo get github.com\u002Fgorilla\u002Fwebsocket\ngo get github.com\u002Fjmoiron\u002Fsqlx\u003C\u002Fcode>\u003C\u002Fpre>\u003Cp> \u003C\u002Fp>\u003Ch3>การตั้งค่าฐานข้อมูลสำหรับเก็บประวัติการแชท\u003C\u002Fh3>\u003Cp>ไฟล์ schema.sql\u003C\u002Fp>\u003Cpre>\u003Ccode class=\"language-plaintext\">CREATE TABLE messages (\n    id SERIAL PRIMARY KEY,\n    content TEXT NOT NULL,\n    sender TEXT NOT NULL,\n    timestamp TIMESTAMP DEFAULT CURRENT_TIMESTAMP\n);\u003C\u002Fcode>\u003C\u002Fpre>\u003Cp> \u003C\u002Fp>\u003Ch3>การสร้าง GraphQL Schema สำหรับเก็บประวัติแชท\u003C\u002Fh3>\u003Cp>ไฟล์ schema.graphql\u003C\u002Fp>\u003Cpre>\u003Ccode class=\"language-plaintext\">type Query {\n  messages: [Message!]!\n}\n\ntype Mutation {\n  sendMessage(content: String!, sender: String!): Message!\n}\n\ntype Subscription {\n  messageAdded: Message!\n}\n\ntype Message {\n  id: ID!\n  content: String!\n  sender: String!\n  timestamp: String!\n}\u003C\u002Fcode>\u003C\u002Fpre>\u003Cp> \u003C\u002Fp>\u003Ch3>การสร้าง Resolver เพื่อเชื่อมต่อกับฐานข้อมูล\u003C\u002Fh3>\u003Cp>ไฟล์ resolver.go\u003C\u002Fp>\u003Cpre>\u003Ccode class=\"language-plaintext\">package main\n\nimport (\n    \"context\"\n    \"database\u002Fsql\"\n    \"fmt\"\n    \"sync\"\n    \"time\"\n\n    _ \"github.com\u002Flib\u002Fpq\"\n)\n\ntype Message struct {\n    ID        int       `json:\"id\"`\n    Content   string    `json:\"content\"`\n    Sender    string    `json:\"sender\"`\n    Timestamp time.Time `json:\"timestamp\"`\n}\n\ntype Resolver struct {\n    mu          sync.Mutex\n    db          *sql.DB\n    subscribers map[string]chan Message\n}\n\nfunc NewResolver(db *sql.DB) *Resolver {\n    return &Resolver{\n        db:          db,\n        subscribers: make(map[string]chan Message),\n    }\n}\n\nfunc (r *Resolver) Query_messages(ctx context.Context) ([]Message, error) {\n    rows, err := r.db.Query(\"SELECT id, content, sender, timestamp FROM messages ORDER BY timestamp DESC LIMIT 50\")\n    if err != nil {\n        return nil, err\n    }\n    defer rows.Close()\n\n    var messages []Message\n    for rows.Next() {\n        var msg Message\n        if err := rows.Scan(&msg.ID, &msg.Content, &msg.Sender, &msg.Timestamp); err != nil {\n            return nil, err\n        }\n        messages = append(messages, msg)\n    }\n    return messages, nil\n}\n\nfunc (r *Resolver) Mutation_sendMessage(ctx context.Context, content string, sender string) (Message, error) {\n    var message Message\n    err := r.db.QueryRow(\"INSERT INTO messages (content, sender) VALUES ($1, $2) RETURNING id, content, sender, timestamp\", content, sender).\n        Scan(&message.ID, &message.Content, &message.Sender, &message.Timestamp)\n    if err != nil {\n        return Message{}, err\n    }\n\n    r.mu.Lock()\n    for _, ch := range r.subscribers {\n        ch <- message\n    }\n    r.mu.Unlock()\n    return message, nil\n}\n\nfunc (r *Resolver) Subscription_messageAdded(ctx context.Context) (<-chan Message, error) {\n    id := fmt.Sprintf(\"%d\", len(r.subscribers))\n    r.mu.Lock()\n    ch := make(chan Message)\n    r.subscribers[id] = ch\n    r.mu.Unlock()\n\n    go func() {\n        <-ctx.Done()\n        r.mu.Lock()\n        delete(r.subscribers, id)\n        close(ch)\n        r.mu.Unlock()\n    }()\n    return ch, nil\n}\u003C\u002Fcode>\u003C\u002Fpre>\u003Cp> \u003C\u002Fp>\u003Ch3>สร้าง WebSocket Server และเชื่อมต่อกับฐานข้อมูล\u003C\u002Fh3>\u003Cp>ไฟล์ server.go\u003C\u002Fp>\u003Cpre>\u003Ccode class=\"language-plaintext\">package main\n\nimport (\n    \"database\u002Fsql\"\n    \"log\"\n    \"net\u002Fhttp\"\n    \"github.com\u002F99designs\u002Fgqlgen\u002Fgraphql\u002Fhandler\"\n    \"github.com\u002F99designs\u002Fgqlgen\u002Fgraphql\u002Fplayground\"\n)\n\nfunc main() {\n    db, err := sql.Open(\"postgres\", \"user=postgres password=secret dbname=chat sslmode=disable\")\n    if err != nil {\n        log.Fatal(err)\n    }\n    defer db.Close()\n\n    resolver := NewResolver(db)\n    srv := handler.NewDefaultServer(NewExecutableSchema(Config{Resolvers: resolver}))\n\n    http.Handle(\"\u002F\", playground.Handler(\"GraphQL Playground\", \"\u002Fquery\"))\n    http.Handle(\"\u002Fquery\", srv)\n\n    log.Println(\"Chat Server with Database running at http:\u002F\u002Flocalhost:8080\")\n    log.Fatal(http.ListenAndServe(\":8080\", nil))\n}\u003C\u002Fcode>\u003C\u002Fpre>\u003Cp> \u003C\u002Fp>\u003Ch4>ท้าให้ลอง!\u003C\u002Fh4>\u003Cp>ลองเพิ่มฟีเจอร์ การค้นหาข้อความเก่า และ การกรองข้อความตามผู้ส่ง ในระบบแชทของคุณ\u003C\u002Fp>\u003Chr>\u003Ch4>EP ถัดไป\u003C\u002Fh4>\u003Cp>ใน EP.36, เราจะเพิ่มระบบ User Authentication ให้กับ WebSocket Chat เพื่อควบคุมสิทธิ์การเข้าถึง 🚀\u003C\u002Fp>","41_1_g8bqjpnllm.webp","https:\u002F\u002Ftwsme-r2.tumwebsme.com\u002Fsclblg987654321\u002F0gb1senrcdbkegy\u002F41_1_g8bqjpnllm.webp","2026-03-04 08:51:19.750Z","",{"keywords":15,"locale":68,"school_blog":78},[16,23,28,33,38,43,48,53,58,63],{"collectionId":17,"collectionName":18,"created":19,"created_by":13,"id":20,"name":21,"updated":22,"updated_by":13},"sclkey987654321","school_keywords","2026-03-04 08:20:14.253Z","ah6lvy4x8qe08l5","Golang","2026-04-10 16:07:26.172Z",{"collectionId":17,"collectionName":18,"created":24,"created_by":13,"id":25,"name":26,"updated":27,"updated_by":13},"2026-03-04 08:20:11.547Z","ey3puyme01a9bsw","Go","2026-04-10 16:07:25.893Z",{"collectionId":17,"collectionName":18,"created":29,"created_by":13,"id":30,"name":31,"updated":32,"updated_by":13},"2026-03-04 08:48:07.088Z","brfbypclggbbkcx","WebSocket API","2026-04-10 16:13:40.594Z",{"collectionId":17,"collectionName":18,"created":34,"created_by":13,"id":35,"name":36,"updated":37,"updated_by":13},"2026-03-04 08:50:52.953Z","aqepcyhdmag8vg4","Chat Storage","2026-04-10 16:14:29.336Z",{"collectionId":17,"collectionName":18,"created":39,"created_by":13,"id":40,"name":41,"updated":42,"updated_by":13},"2026-03-04 08:51:13.649Z","wcctbc65iq5n4bj","GraphQL API","2026-04-10 16:14:34.086Z",{"collectionId":17,"collectionName":18,"created":44,"created_by":13,"id":45,"name":46,"updated":47,"updated_by":13},"2026-03-04 08:51:17.295Z","x5fbzy09361bbm5","Chat Database","2026-04-10 16:14:35.229Z",{"collectionId":17,"collectionName":18,"created":49,"created_by":13,"id":50,"name":51,"updated":52,"updated_by":13},"2026-03-04 08:47:05.949Z","caufix9o52uw4bh","Real-Time Chat","2026-04-10 16:13:23.517Z",{"collectionId":17,"collectionName":18,"created":54,"created_by":13,"id":55,"name":56,"updated":57,"updated_by":13},"2026-03-04 08:46:53.342Z","5ac1xgod1ehyqva","GraphQL Subscriptions","2026-04-10 16:13:20.256Z",{"collectionId":17,"collectionName":18,"created":59,"created_by":13,"id":60,"name":61,"updated":62,"updated_by":13},"2026-03-04 08:34:00.920Z","ecac9y661or1xka","WebSocket","2026-04-10 16:08:05.227Z",{"collectionId":17,"collectionName":18,"created":64,"created_by":13,"id":65,"name":66,"updated":67,"updated_by":13},"2026-03-04 08:50:53.155Z","peza6kmj1144b0x","Chat History","2026-04-10 16:14:29.504Z",{"code":69,"collectionId":70,"collectionName":71,"created":72,"flag":73,"id":74,"is_default":75,"label":76,"updated":77},"th","pbc_1989393366","locales","2026-01-22 10:59:55.832Z","twemoji:flag-thailand","s8wri3bt4vgg2ji",true,"Thai","2026-04-10 15:42:46.614Z",{"category":79,"collectionId":80,"collectionName":81,"created":13,"expand":82,"id":96,"slug":97,"updated":13,"views":98},"wqxt7ag2gn7xcmk","pbc_2105096300","school_blogs",{"category":83},{"blogIds":84,"collectionId":85,"collectionName":86,"created":87,"created_by":13,"id":79,"image":88,"image_alt":13,"image_path":89,"label":90,"name":91,"priority":92,"publish_at":93,"scheduled_at":13,"status":94,"updated":95,"updated_by":13},[],"sclcatblg987654321","school_category_blogs","2026-03-04 08:33:53.210Z","59ty92ns80w_15oc1implw.png","https:\u002F\u002Ftwsme-r2.tumwebsme.com\u002Fsclcatblg987654321\u002Fwqxt7ag2gn7xcmk\u002F59ty92ns80w_15oc1implw.png",{"en":91,"th":91},"Golang The Series",1,"2026-03-16 04:39:38.440Z","published","2026-04-25 02:32:15.470Z","h9qo5h7vbko0hq3","storing-chat-history-websocket-graphql",292,"0gb1senrcdbkegy",[20,25,30,35,40,45,50,55,60,65],"2025-03-13 02:23:55.565Z","เรียนรู้วิธีใช้ WebSocket และ GraphQL Subscription ในการเก็บประวัติการแชทลงฐานข้อมูล รองรับการดึงข้อมูลย้อนหลังและอัปเดตแบบเรียลไทม์ เพื่อให้ระบบแชทของคุณมีความสมบูรณ์มากขึ้น","2026-04-22 07:11:46.021Z",{"th":97,"en":97}]