260316:1117 20260316:1100 Refactor UUID

2026-03-16 11:17:15 +07:00
parent b93cd91325
commit c5c3ed9016
92 changed files with 1726 additions and 620 deletions
@@ -104,7 +104,7 @@ UNIQUE | Role name (

 * * Purpose **: MASTER TABLE storing ALL organizations involved IN the system | COLUMN Name | Data TYPE | Constraints | Description | | ----------------- | ------------ | ----------------------------------- | ---------------------------------------- |
 | id | INT | PRIMARY KEY,
-AUTO_INCREMENT | UNIQUE identifier FOR organization | | organization_code | VARCHAR(20) | NOT NULL,
+AUTO_INCREMENT | UNIQUE identifier FOR organization | | uuid | UUID | NOT NULL, UNIQUE, DEFAULT UUID() | UUID Public Identifier (ADR-019) | | organization_code | VARCHAR(20) | NOT NULL,
 UNIQUE | Organization code (e.g., 'กทท.', 'TEAM') | | organization_name | VARCHAR(255) | NOT NULL | FULL organization name | | is_active | BOOLEAN | DEFAULT TRUE | Active STATUS (1 = active, 0 = inactive) | | created_at | TIMESTAMP | DEFAULT CURRENT_TIMESTAMP | Record creation timestamp | | updated_at | TIMESTAMP | DEFAULT CURRENT_TIMESTAMP ON UPDATE | Last
 UPDATE timestamp |
 | deleted_at | DATETIME | NULL | Soft delete timestamp | ** INDEXES **: - PRIMARY KEY (id) - UNIQUE (organization_code) - INDEX (is_active) ** Relationships **: - Referenced by: users,
@@ -117,7 +117,7 @@ UPDATE timestamp |

  * * Purpose **: MASTER TABLE FOR ALL projects IN the system | COLUMN Name | Data TYPE | Constraints | Description | | ------------ | ------------ | --------------------------- | ----------------------------- |
  | id | INT | PRIMARY KEY,
-  AUTO_INCREMENT | UNIQUE identifier FOR project | | project_code | VARCHAR(50) | NOT NULL,
+  AUTO_INCREMENT | UNIQUE identifier FOR project | | uuid | UUID | NOT NULL, UNIQUE, DEFAULT UUID() | UUID Public Identifier (ADR-019) | | project_code | VARCHAR(50) | NOT NULL,
  UNIQUE | Project code (e.g., 'LCBP3') | | project_name | VARCHAR(255) | NOT NULL | FULL project name | | is_active | TINYINT(1) | DEFAULT 1 | Active STATUS |
 | created_at | TIMESTAMP | DEFAULT CURRENT_TIMESTAMP | Record creation timestamp |
 | updated_at | TIMESTAMP | DEFAULT CURRENT_TIMESTAMP ON UPDATE | Last update timestamp |
@@ -131,7 +131,7 @@ UPDATE timestamp |

  * * Purpose **: MASTER TABLE FOR contracts within projects | COLUMN Name | Data TYPE | Constraints | Description | | ------------- | ------------ | ----------------------------------- | ------------------------------ |
  | id | INT | PRIMARY KEY,
-  AUTO_INCREMENT | UNIQUE identifier FOR contract | | project_id | INT | NOT NULL,
+  AUTO_INCREMENT | UNIQUE identifier FOR contract | | uuid | UUID | NOT NULL, UNIQUE, DEFAULT UUID() | UUID Public Identifier (ADR-019) | | project_id | INT | NOT NULL,
  FK | Reference TO projects TABLE | | contract_code | VARCHAR(50) | NOT NULL,
  UNIQUE | Contract code | | contract_name | VARCHAR(255) | NOT NULL | FULL contract name | | description | TEXT | NULL | Contract description | | start_date | DATE | NULL | Contract START date | | end_date | DATE | NULL | Contract
 END date | | is_active | BOOLEAN | DEFAULT TRUE | Active STATUS | | created_at | TIMESTAMP | DEFAULT CURRENT_TIMESTAMP | Record creation timestamp | | updated_at | TIMESTAMP | DEFAULT CURRENT_TIMESTAMP ON UPDATE | Last
@@ -152,7 +152,7 @@ UPDATE timestamp |

  * * Purpose **: MASTER TABLE storing ALL system users | COLUMN Name | Data TYPE | Constraints | Description | | ----------------------- | ------------ | ----------------------------------- | -------------------------------- |
  | user_id | INT | PRIMARY KEY,
-  AUTO_INCREMENT | UNIQUE identifier FOR user | | username | VARCHAR(50) | NOT NULL,
+  AUTO_INCREMENT | UNIQUE identifier FOR user | | uuid | UUID | NOT NULL, UNIQUE, DEFAULT UUID() | UUID Public Identifier (ADR-019) | | username | VARCHAR(50) | NOT NULL,
  UNIQUE | Login username | | password_hash | VARCHAR(255) | NOT NULL | Hashed PASSWORD (bcrypt) | | first_name | VARCHAR(50) | NULL | User 's first name                |
 | last_name               | VARCHAR(50)  | NULL                                | User' s last name | | email | VARCHAR(100) | NOT NULL,
  UNIQUE | Email address | | line_id | VARCHAR(100) | NULL | LINE messenger ID | | primary_organization_id | INT | NULL,
@@ -335,6 +335,7 @@ SET NULL - INDEX (is_active) - INDEX (email) ** Relationships **: - Parent: orga
 | Column Name               | Data Type    | Constraints                 | Description                                |
 | ------------------------- | ------------ | --------------------------- | ------------------------------------------ |
 | id                        | INT          | PRIMARY KEY, AUTO_INCREMENT | Master correspondence ID                   |
+| uuid                      | UUID   | NOT NULL, UNIQUE, DEFAULT   | UUID Public Identifier (ADR-019)         |
 | correspondence_number     | VARCHAR(100) | NOT NULL                    | Document number (from numbering system)    |
 | correspondence_type_id    | INT          | NOT NULL, FK                | Reference to correspondence_types          |
 | **discipline_id**         | **INT**      | **NULL, FK**                | **[NEW] สาขางาน (ถ้ามี)**                    |
@@ -354,6 +355,7 @@ SET NULL - INDEX (is_active) - INDEX (email) ** Relationships **: - Parent: orga
 * FOREIGN KEY (originator_id) REFERENCES organizations(id) ON DELETE SET NULL
 * FOREIGN KEY (created_by) REFERENCES users(user_id) ON DELETE SET NULL
 * UNIQUE KEY (project_id, correspondence_number)
+* UNIQUE INDEX idx_correspondences_uuid (uuid)
 * INDEX (correspondence_type_id)
 * INDEX (originator_id)
 * INDEX (deleted_at)
@@ -372,6 +374,7 @@ SET NULL - INDEX (is_active) - INDEX (email) ** Relationships **: - Parent: orga
 | Column Name              | Data Type    | Constraints                       | Description                                              |
 | ------------------------ | ------------ | --------------------------------- | -------------------------------------------------------- |
 | id                       | INT          | PRIMARY KEY, AUTO_INCREMENT       | Unique revision ID                                       |
+| uuid                     | UUID   | NOT NULL, UNIQUE, DEFAULT         | UUID Public Identifier (ADR-019)                       |
 | correspondence_id        | INT          | NOT NULL, FK                      | Master correspondence ID                                 |
 | revision_number          | INT          | NOT NULL                          | Revision sequence (0, 1, 2...)                           |
 | revision_label           | VARCHAR(10)  | NULL                              | Display revision (A, B, 1.1...)                          |
@@ -824,6 +827,7 @@ SET NULL - INDEX (is_active) - INDEX (email) ** Relationships **: - Parent: orga
 | Column Name     | Data Type    | Constraints                         | Description                              |
 | --------------- | ------------ | ----------------------------------- | ---------------------------------------- |
 | id              | INT          | PRIMARY KEY, AUTO_INCREMENT         | Unique drawing ID                        |
+| uuid            | UUID   | NOT NULL, UNIQUE, DEFAULT           | UUID Public Identifier (ADR-019)       |
 | project_id      | INT          | NOT NULL, FK                        | Reference to projects                    |
 | condwg_no       | VARCHAR(255) | NOT NULL                            | Contract drawing number                  |
 | title           | VARCHAR(255) | NOT NULL                            | Drawing title                            |
@@ -843,6 +847,7 @@ SET NULL - INDEX (is_active) - INDEX (email) ** Relationships **: - Parent: orga
 * FOREIGN KEY (volume_id) REFERENCES contract_drawing_volumes(id) ON DELETE RESTRICT
 * FOREIGN KEY (updated_by) REFERENCES users(user_id)
 * UNIQUE KEY (project_id, condwg_no)
+* UNIQUE INDEX idx_contract_drawings_uuid (uuid)
 * INDEX (map_cat_id)
 * INDEX (volume_id)
 * INDEX (deleted_at)
@@ -942,6 +947,7 @@ SET NULL - INDEX (is_active) - INDEX (email) ** Relationships **: - Parent: orga
 | Column Name      | Data Type    | Constraints                         | Description                |
 | ---------------- | ------------ | ----------------------------------- | -------------------------- |
 | id               | INT          | PRIMARY KEY, AUTO_INCREMENT         | Unique drawing ID          |
+| uuid             | UUID   | NOT NULL, UNIQUE, DEFAULT           | UUID Public Identifier (ADR-019) |
 | project_id       | INT          | NOT NULL, FK                        | Reference to projects      |
 | drawing_number   | VARCHAR(100) | NOT NULL, UNIQUE                    | Shop drawing number        |
 | main_category_id | INT          | NOT NULL, FK                        | Reference to main category |
@@ -955,6 +961,7 @@ SET NULL - INDEX (is_active) - INDEX (email) ** Relationships **: - Parent: orga

 * PRIMARY KEY (id)
 * UNIQUE (drawing_number)
+* UNIQUE INDEX idx_shop_drawings_uuid (uuid)
 * FOREIGN KEY (project_id) REFERENCES projects(id)
 * FOREIGN KEY (main_category_id) REFERENCES shop_drawing_main_categories(id)
 * FOREIGN KEY (sub_category_id) REFERENCES shop_drawing_sub_categories(id)
@@ -986,6 +993,7 @@ SET NULL - INDEX (is_active) - INDEX (email) ** Relationships **: - Parent: orga
 | Column Name               | Data Type        | Constraints                 | Description                              |
 | ------------------------- | ---------------- | --------------------------- | ---------------------------------------- |
 | id                        | INT              | PRIMARY KEY, AUTO_INCREMENT | Unique revision ID                       |
+| uuid                      | UUID       | NOT NULL, UNIQUE, DEFAULT   | UUID Public Identifier (ADR-019)       |
 | shop_drawing_id           | INT              | NOT NULL, FK                | Master shop drawing ID                   |
 | revision_number           | INT              | NOT NULL                    | Revision sequence (0, 1, 2...)           |
 | revision_label            | VARCHAR(10)      | NULL                        | Display revision (A, B, C...)            |
@@ -1000,6 +1008,7 @@ SET NULL - INDEX (is_active) - INDEX (email) ** Relationships **: - Parent: orga
 * PRIMARY KEY (id)
 * FOREIGN KEY (shop_drawing_id) REFERENCES shop_drawings(id) ON DELETE CASCADE
 * UNIQUE KEY (shop_drawing_id, revision_number)
+* UNIQUE INDEX idx_shop_drawing_revisions_uuid (uuid)
 * INDEX (revision_date)

 **Relationships**:
@@ -1053,6 +1062,7 @@ SET NULL - INDEX (is_active) - INDEX (email) ** Relationships **: - Parent: orga
 | Column Name      | Data Type    | Constraints                         | Description                |
 | ---------------- | ------------ | ----------------------------------- | -------------------------- |
 | id               | INT          | PRIMARY KEY, AUTO_INCREMENT         | Unique drawing ID          |
+| uuid             | UUID   | NOT NULL, UNIQUE, DEFAULT           | UUID Public Identifier (ADR-019) |
 | project_id       | INT          | NOT NULL, FK                        | Reference to projects      |
 | drawing_number   | VARCHAR(100) | NOT NULL, UNIQUE                    | AS Built drawing number    |
 | main_category_id | INT          | NOT NULL, FK                        | Reference to main category |
@@ -1066,6 +1076,7 @@ SET NULL - INDEX (is_active) - INDEX (email) ** Relationships **: - Parent: orga

 * PRIMARY KEY (id)
 * UNIQUE (drawing_number)
+* UNIQUE INDEX idx_asbuilt_drawings_uuid (uuid)
 * FOREIGN KEY (project_id) REFERENCES projects(id)
 * FOREIGN KEY (main_category_id) REFERENCES shop_drawing_main_categories(id)
 * FOREIGN KEY (sub_category_id) REFERENCES shop_drawing_sub_categories(id)
@@ -1097,6 +1108,7 @@ SET NULL - INDEX (is_active) - INDEX (email) ** Relationships **: - Parent: orga
 | Column Name           | Data Type    | Constraints                 | Description                    |
 | --------------------- | ------------ | --------------------------- | ------------------------------ |
 | id                    | INT          | PRIMARY KEY, AUTO_INCREMENT | Unique revision ID             |
+| uuid                  | UUID   | NOT NULL, UNIQUE, DEFAULT   | UUID Public Identifier (ADR-019) |
 | asbuilt_drawing_id    | INT          | NOT NULL, FK                | Master AS Built drawing ID     |
 | revision_number       | INT          | NOT NULL                    | Revision sequence (0, 1, 2...) |
 | revision_label        | VARCHAR(10)  | NULL                        | Display revision (A, B, C...)  |
@@ -1111,6 +1123,7 @@ SET NULL - INDEX (is_active) - INDEX (email) ** Relationships **: - Parent: orga
 * PRIMARY KEY (id)
 * FOREIGN KEY (asbuilt_drawing_id) REFERENCES asbuilt_drawings(id) ON DELETE CASCADE
 * UNIQUE KEY (asbuilt_drawing_id, revision_number)
+* UNIQUE INDEX idx_asbuilt_drawing_revisions_uuid (uuid)
 * INDEX (revision_date)

 **Relationships**:
@@ -1229,6 +1242,7 @@ SET NULL - INDEX (is_active) - INDEX (email) ** Relationships **: - Parent: orga
 | Column Name             | Data Type    | Constraints                         | Description                               |
 | ----------------------- | ------------ | ----------------------------------- | ----------------------------------------- |
 | id                      | INT          | PRIMARY KEY, AUTO_INCREMENT         | Unique circulation ID                     |
+| uuid                    | UUID   | NOT NULL, UNIQUE, DEFAULT           | UUID Public Identifier (ADR-019)        |
 | correspondence_id       | INT          | UNIQUE, FK                          | Link to correspondence (1:1 relationship) |
 | organization_id         | INT          | NOT NULL, FK                        | Organization that owns this circulation   |
 | circulation_no          | VARCHAR(100) | NOT NULL                            | Circulation sheet number                  |
@@ -1249,6 +1263,7 @@ SET NULL - INDEX (is_active) - INDEX (email) ** Relationships **: - Parent: orga
 * FOREIGN KEY (circulation_status_code) REFERENCES circulation_status_codes(code)
 * FOREIGN KEY (created_by_user_id) REFERENCES users(user_id)
 * INDEX (organization_id)
+* UNIQUE INDEX idx_circulations_uuid (uuid)
 * INDEX (circulation_status_code)
 * INDEX (created_by_user_id)

@@ -1338,6 +1353,7 @@ SET NULL - INDEX (is_active) - INDEX (email) ** Relationships **: - Parent: orga
 | Column Name         | Data Type    | Constraints                 | Description                                                              |
 | ------------------- | ------------ | --------------------------- | ------------------------------------------------------------------------ |
 | id                  | INT          | PRIMARY KEY, AUTO_INCREMENT | Unique attachment ID                                                     |
+| uuid                | UUID   | NOT NULL, UNIQUE, DEFAULT   | UUID Public Identifier (ADR-019)                                       |
 | original_filename   | VARCHAR(255) | NOT NULL                    | Original filename from upload                                            |
 | stored_filename     | VARCHAR(255) | NOT NULL                    | System-generated unique filename                                         |
 | file_path           | VARCHAR(500) | NOT NULL                    | Full file path on server (/share/dms-data/)                              |
@@ -1358,6 +1374,7 @@ SET NULL - INDEX (is_active) - INDEX (email) ** Relationships **: - Parent: orga
 * INDEX (stored_filename)
 * INDEX (mime_type)
 * INDEX (uploaded_by_user_id)
+* UNIQUE INDEX idx_attachments_uuid (uuid)
 * INDEX (created_at)
 * INDEX (reference_date)

@@ -1820,6 +1837,7 @@ SET NULL - INDEX (is_active) - INDEX (email) ** Relationships **: - Parent: orga
 | Column Name       | Data Type    | Constraints                 | Description               |
 | :---------------- | :----------- | :-------------------------- | :------------------------ |
 | id                | INT          | PRIMARY KEY, AUTO_INCREMENT | Unique notification ID    |
+| uuid              | UUID   | NOT NULL, DEFAULT           | UUID Public Identifier (ADR-019) |
 | user_id           | INT          | NOT NULL, FK                | Recipient user ID         |
 | title             | VARCHAR(255) | NOT NULL                    | Notification title        |
 | message           | TEXT         | NOT NULL                    | Notification body         |
@@ -1836,6 +1854,7 @@ SET NULL - INDEX (is_active) - INDEX (email) ** Relationships **: - Parent: orga
 * INDEX idx_notif_type (notification_type)
 * INDEX idx_notif_read (is_read)
 * INDEX idx_notif_created (created_at)
+* INDEX idx_notifications_uuid (uuid)

 **Partitioning**:
 * **PARTITION BY RANGE (YEAR(created_at))**: แบ่ง Partition รายปี
@@ -23,6 +23,7 @@ CREATE TABLE organization_roles (
 -- ตาราง Master เก็บข้อมูลองค์กรทั้งหมดที่เกี่ยวข้องในระบบ
 CREATE TABLE organizations (
  id INT PRIMARY KEY AUTO_INCREMENT COMMENT 'ID ของตาราง',
+  uuid UUID NOT NULL DEFAULT UUID() COMMENT 'UUID Public Identifier (ADR-019)',
  organization_code VARCHAR(20) NOT NULL UNIQUE COMMENT 'รหัสองค์กร',
  organization_name VARCHAR(255) NOT NULL COMMENT 'ชื่อองค์กร',
  role_id INT COMMENT 'บทบาทขององค์กร',
@@ -31,12 +32,14 @@ CREATE TABLE organizations (
  updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP COMMENT 'วันที่แก้ไขล่าสุด',
  deleted_at DATETIME NULL COMMENT 'วันที่ลบ (Soft Delete)',
  FOREIGN KEY (role_id) REFERENCES organization_roles (id) ON DELETE
-  SET NULL
+  SET NULL,
+    UNIQUE INDEX idx_organizations_uuid (uuid)
 ) ENGINE = InnoDB DEFAULT CHARSET = utf8mb4 COLLATE = utf8mb4_general_ci COMMENT = 'ตาราง Master เก็บข้อมูลองค์กรทั้งหมดที่เกี่ยวข้องในระบบ';

 -- ตาราง Master เก็บข้อมูลโครงการ
 CREATE TABLE projects (
  id INT PRIMARY KEY AUTO_INCREMENT COMMENT 'ID ของตาราง',
+  uuid UUID NOT NULL DEFAULT UUID() COMMENT 'UUID Public Identifier (ADR-019)',
  project_code VARCHAR(50) NOT NULL UNIQUE COMMENT 'รหัสโครงการ',
  project_name VARCHAR(255) NOT NULL COMMENT 'ชื่อโครงการ',
  -- parent_project_id INT COMMENT 'รหัสโครงการหลัก (ถ้ามี)',
@@ -46,12 +49,14 @@ CREATE TABLE projects (
  -- FOREIGN KEY (contractor_organization_id) REFERENCES organizations(id) ON DELETE SET NULL
  created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP COMMENT 'วันที่สร้าง',
  updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP COMMENT 'วันที่แก้ไขล่าสุด',
-  deleted_at DATETIME NULL COMMENT 'วันที่ลบ (Soft Delete)'
+  deleted_at DATETIME NULL COMMENT 'วันที่ลบ (Soft Delete)',
+  UNIQUE INDEX idx_projects_uuid (uuid)
 ) ENGINE = InnoDB DEFAULT CHARSET = utf8mb4 COLLATE = utf8mb4_general_ci COMMENT = 'ตาราง Master เก็บข้อมูลโครงการ';

 -- ตาราง Master เก็บข้อมูลสัญญา
 CREATE TABLE contracts (
  id INT PRIMARY KEY AUTO_INCREMENT COMMENT 'ID ของตาราง',
+  uuid UUID NOT NULL DEFAULT UUID() COMMENT 'UUID Public Identifier (ADR-019)',
  project_id INT NOT NULL,
  contract_code VARCHAR(50) NOT NULL UNIQUE COMMENT 'รหัสสัญญา',
  contract_name VARCHAR(255) NOT NULL COMMENT 'ชื่อสัญญา',
@@ -62,7 +67,8 @@ CREATE TABLE contracts (
  created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP COMMENT 'วันที่สร้าง',
  updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP COMMENT 'วันที่แก้ไขล่าสุด',
  deleted_at DATETIME NULL COMMENT 'วันที่ลบ (Soft Delete)',
-  FOREIGN KEY (project_id) REFERENCES projects (id) ON DELETE CASCADE
+  FOREIGN KEY (project_id) REFERENCES projects (id) ON DELETE CASCADE,
+  UNIQUE INDEX idx_contracts_uuid (uuid)
 ) ENGINE = InnoDB DEFAULT CHARSET = utf8mb4 COLLATE = utf8mb4_general_ci COMMENT = 'ตาราง Master เก็บข้อมูลสัญญา';

 -- =====================================================
@@ -71,6 +77,7 @@ CREATE TABLE contracts (
 -- ตาราง Master เก็บข้อมูลผู้ใช้งาน (User)
 CREATE TABLE users (
  user_id INT PRIMARY KEY AUTO_INCREMENT COMMENT 'ID ของตาราง',
+  uuid UUID NOT NULL DEFAULT UUID() COMMENT 'UUID Public Identifier (ADR-019)',
  username VARCHAR(50) NOT NULL UNIQUE COMMENT 'ชื่อผู้ใช้งาน',
  password_hash VARCHAR(255) NOT NULL COMMENT 'รหัสผ่าน (Hashed)',
  first_name VARCHAR(50) COMMENT 'ชื่อจริง',
@@ -86,7 +93,8 @@ CREATE TABLE users (
  updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP COMMENT 'วันที่แก้ไขล่าสุด',
  deleted_at DATETIME NULL DEFAULT NULL COMMENT 'วันที่ลบ',
  FOREIGN KEY (primary_organization_id) REFERENCES organizations (id) ON DELETE
-  SET NULL
+  SET NULL,
+    UNIQUE INDEX idx_users_uuid (uuid)
 ) ENGINE = InnoDB DEFAULT CHARSET = utf8mb4 COLLATE = utf8mb4_general_ci COMMENT = 'ตาราง Master เก็บข้อมูลผู้ใช้งาน (User)';

 -- ตารางเก็บ Refresh Tokens สำหรับ Authentication
@@ -258,6 +266,7 @@ CREATE TABLE correspondence_status (
 -- ตาราง "แม่" ของเอกสารโต้ตอบ เก็บข้อมูลที่ไม่เปลี่ยนตาม Revision
 CREATE TABLE correspondences (
  id INT PRIMARY KEY AUTO_INCREMENT COMMENT 'ID ของตาราง (นี่คือ "Master ID" ที่ใช้เชื่อมโยง)',
+  uuid UUID NOT NULL DEFAULT UUID() COMMENT 'UUID Public Identifier (ADR-019)',
  correspondence_type_id INT NOT NULL COMMENT 'ประเภทเอกสาร ใช้แบ่งแยกว่าเป็น RFA หรือ อื่นๆ',
  correspondence_number VARCHAR(100) NOT NULL COMMENT 'เลขที่เอกสาร (สร้างจาก DocumentNumberingModule)',
  discipline_id INT NULL COMMENT 'สาขางาน (ถ้ามี)',
@@ -279,7 +288,8 @@ CREATE TABLE correspondences (
    -- Foreign Key ที่รวมเข้ามาจาก ALTER (ระบุชื่อ Constraint ตามที่ต้องการ)
    CONSTRAINT fk_corr_discipline FOREIGN KEY (discipline_id) REFERENCES disciplines (id) ON DELETE
  SET NULL,
-    UNIQUE KEY uq_corr_no_per_project (project_id, correspondence_number)
+    UNIQUE KEY uq_corr_no_per_project (project_id, correspondence_number),
+    UNIQUE INDEX idx_correspondences_uuid (uuid)
 ) ENGINE = InnoDB DEFAULT CHARSET = utf8mb4 COLLATE = utf8mb4_general_ci COMMENT = 'ตาราง "แม่" ของเอกสารโต้ตอบ เก็บข้อมูลที่ไม่เปลี่ยนตาม Revision';

 -- ตารางเชื่อมผู้รับ (TO/CC) สำหรับเอกสารแต่ละฉบับ (M:N)
@@ -299,6 +309,7 @@ CREATE TABLE correspondence_recipients (
 -- ตาราง "ลูก" เก็บประวัติการแก้ไข (Revisions) ของ correspondences (1:N)
 CREATE TABLE correspondence_revisions (
  id INT PRIMARY KEY AUTO_INCREMENT COMMENT 'ID ของ Revision',
+  uuid UUID NOT NULL DEFAULT UUID() COMMENT 'UUID Public Identifier (ADR-019)',
  correspondence_id INT NOT NULL COMMENT 'Master ID',
  revision_number INT NOT NULL COMMENT 'หมายเลข Revision (0, 1, 2...)',
  revision_label VARCHAR(10) COMMENT 'Revision ที่แสดง (เช่น A, B, 1.1)',
@@ -338,7 +349,8 @@ CREATE TABLE correspondence_revisions (
    UNIQUE KEY uq_master_revision_number (correspondence_id, revision_number),
    UNIQUE KEY uq_master_current (correspondence_id, is_current),
    INDEX idx_corr_rev_v_project (v_ref_project_id),
-    INDEX idx_corr_rev_v_subtype (v_doc_subtype)
+    INDEX idx_corr_rev_v_subtype (v_doc_subtype),
+    UNIQUE INDEX idx_correspondence_revisions_uuid (uuid)
 ) ENGINE = InnoDB DEFAULT CHARSET = utf8mb4 COLLATE = utf8mb4_general_ci COMMENT = 'ตาราง "ลูก" เก็บประวัติการแก้ไข (Revisions) ของ correspondences (1 :N)';

 -- ตาราง Master เก็บ Tags ทั้งหมดที่ใช้ในระบบ
@@ -529,6 +541,7 @@ CREATE TABLE contract_drawing_subcat_cat_maps (
 -- ตาราง Master เก็บข้อมูล "แบบคู่สัญญา"
 CREATE TABLE contract_drawings (
  id INT PRIMARY KEY AUTO_INCREMENT COMMENT 'ID ของตาราง',
+  uuid UUID NOT NULL DEFAULT UUID() COMMENT 'UUID Public Identifier (ADR-019)',
  project_id INT NOT NULL COMMENT 'โครงการ',
  condwg_no VARCHAR(255) NOT NULL COMMENT 'เลขที่แบบสัญญา',
  title VARCHAR(255) NOT NULL COMMENT 'ชื่อแบบสัญญา',
@@ -542,7 +555,8 @@ CREATE TABLE contract_drawings (
  FOREIGN KEY (project_id) REFERENCES projects (id) ON DELETE CASCADE,
  FOREIGN KEY (map_cat_id) REFERENCES contract_drawing_subcat_cat_maps (id) ON DELETE RESTRICT,
  FOREIGN KEY (volume_id) REFERENCES contract_drawing_volumes (id) ON DELETE RESTRICT,
-  UNIQUE KEY ux_condwg_no_project (project_id, condwg_no)
+  UNIQUE KEY ux_condwg_no_project (project_id, condwg_no),
+  UNIQUE INDEX idx_contract_drawings_uuid (uuid)
 ) ENGINE = InnoDB DEFAULT CHARSET = utf8mb4 COLLATE = utf8mb4_general_ci COMMENT = 'ตาราง Master เก็บข้อมูล "แบบคู่สัญญา"';

 -- ตาราง Master สำหรับ "หมวดหมู่หลัก" ของแบบก่อสร้าง
@@ -576,6 +590,7 @@ CREATE TABLE shop_drawing_sub_categories (
 -- ตาราง Master เก็บข้อมูล "แบบก่อสร้าง"
 CREATE TABLE shop_drawings (
  id INT PRIMARY KEY AUTO_INCREMENT COMMENT 'ID ของตาราง',
+  uuid UUID NOT NULL DEFAULT UUID() COMMENT 'UUID Public Identifier (ADR-019)',
  project_id INT NOT NULL COMMENT 'โครงการ',
  drawing_number VARCHAR(100) NOT NULL COMMENT 'เลขที่ Shop Drawing',
  main_category_id INT NOT NULL COMMENT 'หมวดหมู่หลัก',
@@ -587,12 +602,14 @@ CREATE TABLE shop_drawings (
  FOREIGN KEY (project_id) REFERENCES projects (id),
  FOREIGN KEY (main_category_id) REFERENCES shop_drawing_main_categories (id),
  FOREIGN KEY (sub_category_id) REFERENCES shop_drawing_sub_categories (id),
-  UNIQUE KEY ux_shop_dwg_no_project (project_id, drawing_number)
+  UNIQUE KEY ux_shop_dwg_no_project (project_id, drawing_number),
+  UNIQUE INDEX idx_shop_drawings_uuid (uuid)
 ) ENGINE = InnoDB DEFAULT CHARSET = utf8mb4 COLLATE = utf8mb4_general_ci COMMENT = 'ตาราง Master เก็บข้อมูล "แบบก่อสร้าง"';

 -- ตาราง "ลูก" เก็บประวัติ (Revisions) ของ shop_drawings (1:N)
 CREATE TABLE shop_drawing_revisions (
  id INT PRIMARY KEY AUTO_INCREMENT COMMENT 'ID ของ Revision',
+  uuid UUID NOT NULL DEFAULT UUID() COMMENT 'UUID Public Identifier (ADR-019)',
  shop_drawing_id INT NOT NULL COMMENT 'Master ID',
  revision_number INT NOT NULL COMMENT 'หมายเลข Revision (เช่น 0, 1, 2...)',
  revision_label VARCHAR(10) COMMENT 'Revision ที่แสดง (เช่น A, B, 1.1)',
@@ -610,7 +627,8 @@ CREATE TABLE shop_drawing_revisions (
    FOREIGN KEY (updated_by) REFERENCES users (user_id) ON DELETE
  SET NULL,
    UNIQUE KEY ux_sd_rev_drawing_revision (shop_drawing_id, revision_number),
-    UNIQUE KEY uq_sd_current (shop_drawing_id, is_current)
+    UNIQUE KEY uq_sd_current (shop_drawing_id, is_current),
+    UNIQUE INDEX idx_shop_drawing_revisions_uuid (uuid)
 ) ENGINE = InnoDB DEFAULT CHARSET = utf8mb4 COLLATE = utf8mb4_general_ci COMMENT = 'ตาราง "ลูก" เก็บประวัติ (Revisions) ของ shop_drawings (1:N)';

 -- ตารางเชื่อมระหว่าง shop_drawing_revisions กับ contract_drawings (M:N)
@@ -628,6 +646,7 @@ CREATE TABLE shop_drawing_revision_contract_refs (
 -- ตาราง Master เก็บข้อมูล "AS Built"
 CREATE TABLE asbuilt_drawings (
  id INT PRIMARY KEY AUTO_INCREMENT COMMENT 'ID ของตาราง',
+  uuid UUID NOT NULL DEFAULT UUID() COMMENT 'UUID Public Identifier (ADR-019)',
  project_id INT NOT NULL COMMENT 'โครงการ',
  drawing_number VARCHAR(100) NOT NULL COMMENT 'เลขที่ AS Built Drawing',
  main_category_id INT NOT NULL COMMENT 'หมวดหมู่หลัก',
@@ -639,12 +658,14 @@ CREATE TABLE asbuilt_drawings (
  FOREIGN KEY (project_id) REFERENCES projects (id),
  FOREIGN KEY (main_category_id) REFERENCES shop_drawing_main_categories (id),
  FOREIGN KEY (sub_category_id) REFERENCES shop_drawing_sub_categories (id),
-  UNIQUE KEY ux_asbuilt_no_project (project_id, drawing_number)
+  UNIQUE KEY ux_asbuilt_no_project (project_id, drawing_number),
+  UNIQUE INDEX idx_asbuilt_drawings_uuid (uuid)
 ) ENGINE = InnoDB DEFAULT CHARSET = utf8mb4 COLLATE = utf8mb4_general_ci COMMENT = 'ตาราง Master เก็บข้อมูล "แบบ AS Built"';

 -- ตาราง "ลูก" เก็บประวัติ (Revisions) ของ AS Built (1:N)
 CREATE TABLE asbuilt_drawing_revisions (
  id INT PRIMARY KEY AUTO_INCREMENT COMMENT 'ID ของ Revision',
+  uuid UUID NOT NULL DEFAULT UUID() COMMENT 'UUID Public Identifier (ADR-019)',
  asbuilt_drawing_id INT NOT NULL COMMENT 'Master ID',
  revision_number INT NOT NULL COMMENT 'หมายเลข Revision (เช่น 0, 1, 2...)',
  revision_label VARCHAR(10) COMMENT 'Revision ที่แสดง (เช่น A, B, 1.1)',
@@ -662,7 +683,8 @@ CREATE TABLE asbuilt_drawing_revisions (
    FOREIGN KEY (updated_by) REFERENCES users (user_id) ON DELETE
  SET NULL,
    UNIQUE KEY ux_asbuilt_rev_drawing_revision (asbuilt_drawing_id, revision_number),
-    UNIQUE KEY uq_asbuilt_current (asbuilt_drawing_id, is_current)
+    UNIQUE KEY uq_asbuilt_current (asbuilt_drawing_id, is_current),
+    UNIQUE INDEX idx_asbuilt_drawing_revisions_uuid (uuid)
 ) ENGINE = InnoDB DEFAULT CHARSET = utf8mb4 COLLATE = utf8mb4_general_ci COMMENT = 'ตาราง "ลูก" เก็บประวัติ (Revisions) ของ asbuilt_drawings (1:N)';

 -- ตารางเชื่อมระหว่าง asbuilt_drawing_revisions กับ shop_drawing_revisions (M:N)
@@ -744,6 +766,7 @@ CREATE TABLE circulation_status_codes (
 -- ตาราง "แม่" ของใบเวียนเอกสารภายใน
 CREATE TABLE circulations (
  id INT PRIMARY KEY AUTO_INCREMENT COMMENT 'ID ของตารางใบเวียน',
+  uuid UUID NOT NULL DEFAULT UUID() COMMENT 'UUID Public Identifier (ADR-019)',
  correspondence_id INT UNIQUE COMMENT 'ID ของเอกสาร (จากตาราง correspondences)',
  organization_id INT NOT NULL COMMENT 'ID ขององค์กรณ์ที่เป็นเจ้าของใบเวียนนี้',
  circulation_no VARCHAR(100) NOT NULL COMMENT 'เลขที่ใบเวียน',
@@ -757,7 +780,8 @@ CREATE TABLE circulations (
  FOREIGN KEY (correspondence_id) REFERENCES correspondences (id),
  FOREIGN KEY (organization_id) REFERENCES organizations (id),
  FOREIGN KEY (circulation_status_code) REFERENCES circulation_status_codes (code),
-  FOREIGN KEY (created_by_user_id) REFERENCES users (user_id)
+  FOREIGN KEY (created_by_user_id) REFERENCES users (user_id),
+  UNIQUE INDEX idx_circulations_uuid (uuid)
 ) ENGINE = InnoDB DEFAULT CHARSET = utf8mb4 COLLATE = utf8mb4_general_ci COMMENT = 'ตาราง "แม่" ของใบเวียนเอกสารภายใน';

 -- =====================================================
@@ -800,6 +824,7 @@ CREATE TABLE transmittal_items (
 -- เหตุผล: จัดการไฟล์ขยะ (Orphan Files) และตรวจสอบความถูกต้องไฟล์
 CREATE TABLE attachments (
  id INT PRIMARY KEY AUTO_INCREMENT COMMENT 'ID ของไฟล์แนบ',
+  uuid UUID NOT NULL DEFAULT UUID() COMMENT 'UUID Public Identifier (ADR-019)',
  original_filename VARCHAR(255) NOT NULL COMMENT 'ชื่อไฟล์ดั้งเดิมตอนอัปโหลด',
  stored_filename VARCHAR(255) NOT NULL COMMENT 'ชื่อไฟล์ที่เก็บจริงบน Server (ป้องกันชื่อซ้ำ)',
  file_path VARCHAR(500) NOT NULL COMMENT 'Path ที่เก็บไฟล์ (บน QNAP / share / dms - data /)',
@@ -813,7 +838,8 @@ CREATE TABLE attachments (
  CHECKSUM VARCHAR(64) NULL COMMENT 'SHA-256 Checksum',
  reference_date DATE NULL COMMENT 'Date used for folder structure (e.g. Issue Date) to prevent broken paths',
  FOREIGN KEY (uploaded_by_user_id) REFERENCES users (user_id) ON DELETE CASCADE,
-  INDEX idx_attachments_reference_date (reference_date)
+  INDEX idx_attachments_reference_date (reference_date),
+  UNIQUE INDEX idx_attachments_uuid (uuid)
 ) ENGINE = InnoDB DEFAULT CHARSET = utf8mb4 COLLATE = utf8mb4_general_ci COMMENT = 'ตาราง "กลาง" เก็บไฟล์แนบทั้งหมดของระบบ';

 -- ตารางเชื่อม correspondences กับ attachments (M:N)
@@ -1198,6 +1224,7 @@ PARTITION BY RANGE (YEAR(created_at)) (
 -- ตารางสำหรับจัดการการแจ้งเตือน (Email/Line/System)
 CREATE TABLE notifications (
  id INT NOT NULL AUTO_INCREMENT COMMENT 'ID ของการแจ้งเตือน',
+  uuid UUID NOT NULL DEFAULT UUID() COMMENT 'UUID Public Identifier (ADR-019)',
  user_id INT NOT NULL COMMENT 'ID ผู้ใช้',
  title VARCHAR(255) NOT NULL COMMENT 'หัวข้อการแจ้งเตือน',
  message TEXT NOT NULL COMMENT 'รายละเอียดการแจ้งเตือน',
@@ -1213,7 +1240,8 @@ CREATE TABLE notifications (
  INDEX idx_notif_user (user_id),
  INDEX idx_notif_type (notification_type),
  INDEX idx_notif_read (is_read),
-  INDEX idx_notif_created (created_at)
+  INDEX idx_notif_created (created_at),
+  INDEX idx_notifications_uuid (uuid)
 ) ENGINE = InnoDB DEFAULT CHARSET = utf8mb4 COLLATE = utf8mb4_general_ci COMMENT = 'ตารางสำหรับจัดการการแจ้งเตือน (Email / Line / System)' -- [เพิ่ม] คำสั่ง Partition
 PARTITION BY RANGE (YEAR(created_at)) (
  PARTITION p_old
@@ -120,17 +120,21 @@ CREATE INDEX idx_audit_request_id ON audit_logs (request_id);
 -- View แสดง Revision "ปัจจุบัน" ของ correspondences ทั้งหมด (ที่ไม่ใช่ RFA)
 CREATE VIEW v_current_correspondences AS
 SELECT c.id AS correspondence_id,
+  c.uuid AS correspondence_uuid,
  c.correspondence_number,
  c.correspondence_type_id,
  ct.type_code AS correspondence_type_code,
  ct.type_name AS correspondence_type_name,
  c.project_id,
+  p.uuid AS project_uuid,
  p.project_code,
  p.project_name,
  c.originator_id,
+  org.uuid AS originator_uuid,
  org.organization_code AS originator_code,
  org.organization_name AS originator_name,
  cr.id AS revision_id,
+  cr.uuid AS revision_uuid,
  cr.revision_number,
  cr.revision_label,
  cr.subject,
@@ -162,6 +166,7 @@ WHERE cr.is_current = TRUE
 -- View แสดง Revision "ปัจจุบัน" ของ rfa_revisions ทั้งหมด
 CREATE VIEW v_current_rfas AS
 SELECT r.id AS rfa_id,
+  c.uuid AS correspondence_uuid,
  r.rfa_type_id,
  rt.type_code AS rfa_type_code,
  rt.type_name_th AS rfa_type_name_th,
@@ -172,11 +177,14 @@ SELECT r.id AS rfa_id,
  d.discipline_code,
  -- ✅ Join เพิ่มเพื่อแสดง code
  c.project_id,
+  p.uuid AS project_uuid,
  p.project_code,
  p.project_name,
  c.originator_id,
+  org.uuid AS originator_uuid,
  org.organization_name AS originator_name,
  rr.id AS revision_id,
+  cr.uuid AS revision_uuid,
  cr.revision_number,
  cr.revision_label,
  cr.subject,
@@ -211,12 +219,15 @@ WHERE cr.is_current = TRUE
 -- View แสดงความสัมพันธ์ทั้งหมดระหว่าง Contract, Project, และ Organization
 CREATE VIEW v_contract_parties_all AS
 SELECT c.id AS contract_id,
+  c.uuid AS contract_uuid,
  c.contract_code,
  c.contract_name,
  p.id AS project_id,
+  p.uuid AS project_uuid,
  p.project_code,
  p.project_name,
  o.id AS organization_id,
+  o.uuid AS organization_uuid,
  o.organization_code,
  o.organization_name,
  co.role_in_contract
@@ -380,8 +391,10 @@ WHERE p.is_active = 1
 CREATE VIEW v_documents_with_attachments AS
 SELECT 'CORRESPONDENCE' AS document_type,
  c.id AS document_id,
+  c.uuid AS document_uuid,
  c.correspondence_number AS document_number,
  c.project_id,
+  p.uuid AS project_uuid,
  p.project_code,
  p.project_name,
  COUNT(ca.attachment_id) AS attachment_count,
@@ -399,8 +412,10 @@ GROUP BY c.id,
 UNION ALL
 SELECT 'CIRCULATION' AS document_type,
  circ.id AS document_id,
+  circ.uuid AS document_uuid,
  circ.circulation_no AS document_number,
  corr.project_id,
+  p.uuid AS project_uuid,
  p.project_code,
  p.project_name,
  COUNT(ca.attachment_id) AS attachment_count,
@@ -418,8 +433,10 @@ GROUP BY circ.id,
 UNION ALL
 SELECT 'SHOP_DRAWING' AS document_type,
  sdr.id AS document_id,
+  sdr.uuid AS document_uuid,
  sd.drawing_number AS document_number,
  sd.project_id,
+  p.uuid AS project_uuid,
  p.project_code,
  p.project_name,
  COUNT(sdra.attachment_id) AS attachment_count,
@@ -438,8 +455,10 @@ GROUP BY sdr.id,
 UNION ALL
 SELECT 'CONTRACT_DRAWING' AS document_type,
  cd.id AS document_id,
+  cd.uuid AS document_uuid,
  cd.condwg_no AS document_number,
  cd.project_id,
+  p.uuid AS project_uuid,
  p.project_code,
  p.project_name,
  COUNT(cda.attachment_id) AS attachment_count,
@@ -0,0 +1,295 @@
+# Implementation Plan: Hybrid UUID Strategy (ADR-019)
+
+**Version:** 1.8.1
+**Created:** 2026-03-16
+**Related ADR:** [ADR-019](../06-Decision-Records/ADR-019-hybrid-identifier-strategy.md)
+
+---
+
+## Overview
+
+This document outlines the step-by-step implementation plan to integrate UUIDv7 public identifiers into the LCBP3-DMS backend, following the hybrid strategy defined in ADR-019.
+
+**Scope:** 14 public-facing tables now have `uuid UUID` columns (MariaDB native type, stored as BINARY(16) internally) in the schema. This plan covers backend code changes to expose UUIDs through the API while keeping INT PKs for internal operations.
+
+---
+
+## Phase 1: Database Foundation (✅ COMPLETED)
+
+- [x] Create ADR-019 document
+- [x] Add `uuid UUID` columns (MariaDB native type) to 14 public-facing tables in schema SQL
+- [x] Add UNIQUE INDEX on each uuid column
+- [x] Update data dictionary with uuid column documentation
+- [x] Update AGENTS.md with ADR-019 reference
+
+### Affected Tables (14)
+
+| # | Table | PK Column | UUID Index |
+|---|-------|-----------|------------|
+| 1 | organizations | id | idx_organizations_uuid |
+| 2 | projects | id | idx_projects_uuid |
+| 3 | contracts | id | idx_contracts_uuid |
+| 4 | users | user_id | idx_users_uuid |
+| 5 | correspondences | id | idx_correspondences_uuid |
+| 6 | correspondence_revisions | id | idx_correspondence_revisions_uuid |
+| 7 | circulations | id | idx_circulations_uuid |
+| 8 | shop_drawings | id | idx_shop_drawings_uuid |
+| 9 | shop_drawing_revisions | id | idx_shop_drawing_revisions_uuid |
+| 10 | contract_drawings | id | idx_contract_drawings_uuid |
+| 11 | asbuilt_drawings | id | idx_asbuilt_drawings_uuid |
+| 12 | asbuilt_drawing_revisions | id | idx_asbuilt_drawing_revisions_uuid |
+| 13 | attachments | id | idx_attachments_uuid |
+| 14 | notifications | id | idx_notifications_uuid |
+
+### Excluded Tables (Shared-PK / Junction — inherit UUID from parent)
+
+- `rfas` — shared PK with `correspondences`
+- `rfa_revisions` — shared PK with `correspondence_revisions`
+- `transmittals` — shared PK with `correspondences`
+- `rfa_items` — junction table (composite PK, no own identity)
+
+---
+
+## Phase 2: Backend — TypeORM Base Entity & UUID Utilities
+
+> **Simplified by MariaDB Native UUID Type:** MariaDB 10.7+ stores UUID as `BINARY(16)` internally but auto-converts to/from string format. No manual binary conversion utilities or TypeORM transformers needed.
+
+### 2.1 Create Base Entity with UUID
+
+**File:** `backend/src/common/entities/uuid-base.entity.ts`
+
+```typescript
+import { Column, BeforeInsert } from 'typeorm';
+import { v7 as uuidv7 } from 'uuid';
+
+export abstract class UuidBaseEntity {
+  @Column({
+    type: 'uuid',
+    unique: true,
+    nullable: false,
+    comment: 'UUID Public Identifier (ADR-019)',
+  })
+  uuid: string;
+
+  @BeforeInsert()
+  generateUuid(): void {
+    if (!this.uuid) {
+      this.uuid = uuidv7();
+    }
+  }
+}
+```
+
+> **Note:** MariaDB native `UUID` type handles string ↔ binary conversion automatically.
+> TypeORM reads/writes UUID as standard string format (8-4-4-4-12) — no transformer required.
+> DB `DEFAULT UUID()` generates UUID v1 as fallback; app generates UUIDv7 via `@BeforeInsert()`.
+
+### 2.2 Install uuid Package
+
+```bash
+cd backend
+npm install uuid
+npm install -D @types/uuid
+```
+
+---
+
+## Phase 3: Backend — Update Existing Entities
+
+For each of the 14 public-facing entities, extend or mix in the UUID column:
+
+### Pattern: Extend UuidBaseEntity
+
+```typescript
+// Example: correspondence.entity.ts
+import { Entity, PrimaryGeneratedColumn } from 'typeorm';
+import { UuidBaseEntity } from '../../common/entities/uuid-base.entity';
+
+@Entity('correspondences')
+export class Correspondence extends UuidBaseEntity {
+  @PrimaryGeneratedColumn()
+  id: number;
+
+  // ... existing columns (uuid + @BeforeInsert inherited from UuidBaseEntity)
+}
+```
+
+### Entities to Update
+
+| Entity File | Table |
+|-------------|-------|
+| `organization.entity.ts` | organizations |
+| `project.entity.ts` | projects |
+| `contract.entity.ts` | contracts |
+| `user.entity.ts` | users |
+| `correspondence.entity.ts` | correspondences |
+| `correspondence-revision.entity.ts` | correspondence_revisions |
+| `circulation.entity.ts` | circulations |
+| `shop-drawing.entity.ts` | shop_drawings |
+| `shop-drawing-revision.entity.ts` | shop_drawing_revisions |
+| `contract-drawing.entity.ts` | contract_drawings |
+| `asbuilt-drawing.entity.ts` | asbuilt_drawings |
+| `asbuilt-drawing-revision.entity.ts` | asbuilt_drawing_revisions |
+| `attachment.entity.ts` | attachments |
+| `notification.entity.ts` | notifications |
+
+---
+
+## Phase 4: Backend — API Layer Changes
+
+### 4.1 UUID Pipe (Parameter Validation)
+
+**File:** `backend/src/common/pipes/parse-uuid.pipe.ts`
+
+```typescript
+import { PipeTransform, Injectable, BadRequestException } from '@nestjs/common';
+import { validate as uuidValidate, version as uuidVersion } from 'uuid';
+
+@Injectable()
+export class ParseUuidPipe implements PipeTransform<string> {
+  transform(value: string): string {
+    if (!uuidValidate(value) || uuidVersion(value) !== 7) {
+      throw new BadRequestException(`Invalid UUID: ${value}`);
+    }
+    return value;
+  }
+}
+```
+
+### 4.2 Controller Pattern — UUID in URLs
+
+```typescript
+// BEFORE (INT):  GET /api/correspondences/123
+// AFTER (UUID):  GET /api/correspondences/01912345-6789-7abc-...
+
+@Get(':uuid')
+findOne(@Param('uuid', ParseUuidPipe) uuid: string) {
+  return this.service.findByUuid(uuid);
+}
+```
+
+### 4.3 Service Pattern — Internal UUID Lookup
+
+```typescript
+async findByUuid(uuid: string): Promise<CorrespondenceDto> {
+  const entity = await this.repository.findOne({
+    where: { uuid },
+    relations: ['revisions', 'recipients'],
+  });
+  if (!entity) throw new NotFoundException();
+  return this.mapToDto(entity);
+}
+```
+
+### 4.4 DTO Pattern — UUID Exposure
+
+```typescript
+// Response DTO exposes uuid, hides id
+export class CorrespondenceResponseDto {
+  uuid: string;              // ✅ Public identifier
+  correspondenceNumber: string;
+  // id: number;             // ❌ Never expose INT id
+}
+```
+
+### 4.5 Migration Helper — findByUuidOrId
+
+During transition, support both identifiers:
+
+```typescript
+async findByUuidOrId(identifier: string): Promise<Entity> {
+  const isUuid = uuidValidate(identifier);
+  if (isUuid) {
+    return this.repository.findOne({ where: { uuid: identifier } });
+  }
+  // Fallback to INT (internal/admin use only)
+  const id = parseInt(identifier, 10);
+  if (isNaN(id)) throw new BadRequestException();
+  return this.repository.findOne({ where: { id } });
+}
+```
+
+---
+
+## Phase 5: Frontend — UUID Integration
+
+### 5.1 API Client Updates
+
+- Update all API calls to use UUID in URL paths instead of INT id
+- Update TanStack Query cache keys to use UUID
+- Update Zustand stores to key by UUID
+
+### 5.2 Route Parameters
+
+```typescript
+// BEFORE: /correspondences/[id]
+// AFTER:  /correspondences/[uuid]
+```
+
+### 5.3 Form Handling
+
+- Hidden `uuid` field in forms for edit operations
+- No changes needed for create operations (UUID generated server-side)
+
+---
+
+## Phase 6: Testing & Verification
+
+### 6.1 Unit Tests
+
+- UUID generation produces valid UUIDv7
+- UuidBaseEntity `@BeforeInsert()` auto-generates UUID when not provided
+- ParseUuidPipe rejects invalid UUIDs
+- MariaDB native UUID column stores and retrieves string format correctly
+
+### 6.2 Integration Tests
+
+- Entity creation auto-generates UUID
+- API endpoints accept UUID parameters
+- UUID lookup returns correct records
+- Duplicate UUID detection (unique constraint)
+
+### 6.3 Performance Verification
+
+- Benchmark: UUID lookup via UNIQUE INDEX vs INT PK lookup
+- Acceptable threshold: < 2x overhead on single-row lookups
+- Verify B-tree ordering with time-sorted UUIDv7
+
+---
+
+## Implementation Order (Priority)
+
+| Order | Task | Effort | Depends On |
+|-------|------|--------|------------|
+| 1 | UuidBaseEntity (no transformer needed — MariaDB native UUID) | S | Phase 1 |
+| 2 | Install `uuid` package | XS | — |
+| 3 | Update 14 entity files with uuid column | M | Task 1 |
+| 4 | Create ParseUuidPipe | S | — |
+| 5 | Update controllers to use UUID params | L | Tasks 3, 4 |
+| 6 | Update services with findByUuid methods | L | Task 3 |
+| 7 | Update DTOs to expose uuid, hide id | M | Task 3 |
+| 8 | Update frontend API calls | L | Tasks 5, 6, 7 |
+| 9 | Update frontend routes | M | Task 8 |
+| 10 | Write unit + integration tests | M | Tasks 1-7 |
+ำ
+**Estimated Total Effort:** ~3-5 days for backend, ~2-3 days for frontend
+
+---
+
+## Rollback Strategy
+
+If issues arise:
+
+1. **Schema:** UUID columns have `DEFAULT` — existing inserts still work without app changes
+2. **API:** INT-based endpoints can be restored by reverting controller/service changes
+3. **Data:** No data loss — UUID column is additive (no existing columns modified)
+4. **Frontend:** Route parameter changes are reversible
+
+---
+
+## Notes
+
+- **Seed files** do not need UUID values — the `DEFAULT UUID()` clause auto-generates UUIDs at INSERT time
+- **Notifications table** uses a non-unique INDEX (not UNIQUE) for uuid because of its partitioned composite PK `(id, created_at)`
+- **Workflow engine tables** (`workflow_instances`, `workflow_tasks`) already use `CHAR(36)` UUIDs — no changes needed
+- **Shared-PK tables** (`rfas`, `rfa_revisions`, `transmittals`) inherit their parent's UUID via the correspondence relationship
@@ -0,0 +1,478 @@
+# ADR-019: Hybrid Identifier Strategy (INT + UUIDv7)
+
+**Status:** Accepted
+**Date:** 2026-03-12
+**Version:** 1.8.1
+**Decision Makers:** Development Team, Database Architect
+**Related Documents:**
+- [Data Dictionary](../03-Data-and-Storage/03-01-data-dictionary.md)
+- [Database Schema](../03-Data-and-Storage/lcbp3-v1.8.0-schema-02-tables.sql)
+- [ADR-005: Technology Stack](ADR-005-technology-stack.md)
+- [ADR-009: Database Migration Strategy](ADR-009-database-migration-strategy.md)
+- [ADR-016: Security & Authentication](ADR-016-security-authentication.md)
+
+---
+
+## Context and Problem Statement
+
+ระบบ LCBP3-DMS ใช้ `INT AUTO_INCREMENT` เป็น Primary Key ทุกตาราง ซึ่งทำงานได้ดีสำหรับ Internal JOIN/FK แต่มีปัญหาด้านความปลอดภัยและ Scalability:
+
+1. **ID Enumeration Attack:** Sequential INT IDs ถูกเดาได้ง่าย (เช่น `/api/correspondences/1`, `/api/correspondences/2`) ทำให้ผู้ไม่ประสงค์ดีสามารถ Enumerate ข้อมูลได้
+2. **Information Leakage:** INT IDs เปิดเผยจำนวนข้อมูลในระบบ (เช่น `user_id=5` แปลว่ามีผู้ใช้ 5 คน)
+3. **Cross-System Integration:** หากในอนาคตต้องการ Sync ข้อมูลข้ามระบบ INT ID จะชนกัน
+4. **API Security:** OWASP BOLA (Broken Object Level Authorization) แนะนำให้ใช้ Opaque Identifier แทน Sequential ID
+
+ทั้งนี้ ระบบมีข้อจำกัดด้าน Hardware (QNAP NAS) ที่ต้องพิจารณาเรื่อง Performance
+
+---
+
+## Decision Drivers
+
+- **Security:** ป้องกัน ID Enumeration และลดความเสี่ยง OWASP BOLA
+- **Performance:** INT PK ยังคงเป็น Primary Key เพื่อ JOIN/FK Performance บน InnoDB
+- **Backward Compatibility:** ไม่ต้อง Migrate ข้อมูลหรือเปลี่ยน FK Relationships ที่มีอยู่
+- **Simplicity:** เปลี่ยนเฉพาะ Public-Facing Tables (ไม่ใช่ทุกตาราง)
+- **Standards:** UUIDv7 (RFC 9562) เป็น Time-ordered UUID ที่ B-tree friendly
+
+---
+
+## Considered Options
+
+### Option 1: Replace INT with UUID as Primary Key
+
+**Pros:**
+- ✅ Opaque identifier ทุกที่
+
+**Cons:**
+- ❌ FK ทั้งหมดต้องเปลี่ยนเป็น BINARY(16) — Migration ซับซ้อนมาก
+- ❌ JOIN Performance แย่ลง (16 bytes vs 4 bytes)
+- ❌ InnoDB Clustered Index ไม่เรียงลำดับตาม INSERT Time (UUIDv4)
+- ❌ ต้อง Rewrite Backend ทั้งหมด (Entity, DTO, Controller, Service)
+- ❌ Breaking Change กับ Frontend ที่ใช้ INT ID อยู่
+
+### Option 2: UUID as String Column (CHAR(36))
+
+**Pros:**
+- ✅ Human-readable
+
+**Cons:**
+- ❌ ใช้พื้นที่ 36 bytes ต่อ row (vs 16 bytes สำหรับ BINARY)
+- ❌ Index ใหญ่ ช้ากว่า BINARY(16) อย่างมีนัยสำคัญ
+- ❌ Collation issues กับ case-sensitivity
+
+### Option 3: Hybrid INT + UUID (MariaDB Native) ⭐ (Selected)
+
+**Pros:**
+- ✅ INT PK ยังเป็น Internal ID → Performance ไม่เปลี่ยน
+- ✅ UUID เป็น External ID → ปลอดภัย + Space-efficient (BINARY(16) ภายใน)
+- ✅ ไม่ต้อง Migrate FK Relationships
+- ✅ UUIDv7 Time-ordered → B-tree friendly, Index Performance ดี
+- ✅ Backward Compatible — Frontend ค่อยๆ Migrate ได้
+- ✅ ไม่กระทบ Migration Tables (Temporary)
+
+**Cons:**
+- ❌ ต้องเพิ่ม Column ใหม่ + UNIQUE INDEX ทุก Public-Facing Table
+- ❌ Application Layer ต้อง Generate UUIDv7 ตอน INSERT
+- ❌ API Layer ต้อง Resolve UUID → INT สำหรับ Internal Queries
+
+---
+
+## Decision Outcome
+
+**Chosen Option:** Option 3 — Hybrid INT + UUID (MariaDB Native Type)
+
+**Rationale:** เป็นแนวทางที่ Balance ระหว่าง Security, Performance และ Migration Effort ดีที่สุด ไม่ต้อง Rewrite FK ทั้งหมด ไม่ต้อง Migrate ข้อมูล และเพิ่มความปลอดภัยของ API
+
+---
+
+## Technical Specification
+
+### 1. UUID Format
+
+| Property | Value |
+|----------|-------|
+| **Type** | MariaDB Native `UUID` (available since 10.7) |
+| **Storage** | `BINARY(16)` internally (automatic) |
+| **DB Default** | `UUID()` — generates UUID v1 (time-based, fallback for seed data) |
+| **App Generation** | NestJS `@BeforeInsert()` generates UUIDv7 (RFC 9562) for time-ordering |
+| **Display** | Auto-converts to string format (8-4-4-4-12) — no conversion function needed |
+| **Index** | `UNIQUE INDEX` on `uuid` column |
+
+### 2. Column Specification
+
+```sql
+-- Column definition for all public-facing tables (MariaDB 10.7+)
+uuid UUID NOT NULL DEFAULT UUID() COMMENT 'UUID Public Identifier (ADR-019)',
+UNIQUE INDEX idx_{table}_uuid (uuid)
+```
+
+> **Note:** MariaDB native `UUID` type เก็บเป็น `BINARY(16)` ภายใน แต่แสดงผลเป็น String format อัตโนมัติ ไม่ต้องใช้ `BIN_TO_UUID()` / `UUID_TO_BIN()`
+>
+> **DB Default:** `UUID()` สร้าง UUID v1 (สำหรับ Seed Data และ Fallback)
+>
+> **Application Override:** NestJS Entity จะ Generate UUIDv7 เองก่อน INSERT เพื่อให้ได้ True UUIDv7 (Time-ordered, B-tree friendly)
+
+### 3. Tables Requiring UUID Column
+
+#### Tier 1 — Core Entity Tables (Own UUID Column)
+
+| # | Table Name | Current PK | UUID Column | Notes |
+|---|-----------|-----------|-------------|-------|
+| 1 | `users` | `user_id INT AI` | `uuid UUID` | User profiles |
+| 2 | `organizations` | `id INT AI` | `uuid UUID` | Organization data |
+| 3 | `projects` | `id INT AI` | `uuid UUID` | Project data |
+| 4 | `contracts` | `id INT AI` | `uuid UUID` | Contract data |
+| 5 | `correspondences` | `id INT AI` | `uuid UUID` | Main document entity |
+| 6 | `correspondence_revisions` | `id INT AI` | `uuid UUID` | Document versions |
+| 7 | `circulations` | `id INT AI` | `uuid UUID` | Internal circulations |
+| 8 | `shop_drawings` | `id INT AI` | `uuid UUID` | Shop drawing master |
+| 9 | `shop_drawing_revisions` | `id INT AI` | `uuid UUID` | Shop drawing versions |
+| 10 | `contract_drawings` | `id INT AI` | `uuid UUID` | Contract drawing master |
+| 11 | `asbuilt_drawings` | `id INT AI` | `uuid UUID` | As-built drawing master |
+| 12 | `asbuilt_drawing_revisions` | `id INT AI` | `uuid UUID` | As-built drawing versions |
+| 13 | `attachments` | `id INT AI` | `uuid UUID` | File attachments |
+| 14 | `notifications` | `id INT AI` (partitioned) | `uuid UUID` | User notifications |
+
+#### Tier 2 — Shared-PK Tables (Inherit UUID from Parent)
+
+| # | Table Name | Shared PK Source | UUID Resolution |
+|---|-----------|-----------------|-----------------|
+| 1 | `rfas` | `correspondences.id` | Use `correspondences.uuid` |
+| 2 | `rfa_revisions` | `correspondence_revisions.id` | Use `correspondence_revisions.uuid` |
+| 3 | `transmittals` | `correspondences.id` | Use `correspondences.uuid` |
+
+#### Already Using UUID — No Changes Needed
+
+| Table Name | Current PK |
+|-----------|-----------|
+| `workflow_definitions` | `CHAR(36) UUID` |
+| `workflow_instances` | `CHAR(36) UUID` |
+| `workflow_histories` | `CHAR(36) UUID` |
+
+#### Excluded Tables (Internal/Master/Junction)
+
+ตารางต่อไปนี้ **ไม่ต้อง** เพิ่ม UUID Column เพราะเป็น Internal-use only:
+
+- **Master/Lookup:** `organization_roles`, `disciplines`, `correspondence_types`, `correspondence_sub_types`, `correspondence_status`, `rfa_types`, `rfa_status_codes`, `rfa_approve_codes`, `circulation_status_codes`, `tags`
+- **RBAC:** `roles`, `permissions`, `user_assignments`
+- **Junction/Mapping:** `project_organizations`, `contract_organizations`, `correspondence_recipients`, `correspondence_tags`, `correspondence_references`, `contract_drawing_subcat_cat_maps`, `shop_drawing_revision_contract_refs`, `asbuilt_revision_shop_revisions_refs`, all `*_attachments` junction tables
+- **Drawing Categories:** `contract_drawing_volumes`, `contract_drawing_cats`, `contract_drawing_sub_cats`, `shop_drawing_main_categories`, `shop_drawing_sub_categories`
+- **Document Numbering:** `document_number_formats`, `document_number_counters`, `document_number_audit`, `document_number_errors`, `document_number_reservations`
+- **System/Logs:** `json_schemas`, `user_preferences`, `audit_logs`, `search_indices`, `backup_logs`, `refresh_tokens`
+- **Migration (Temporary):** `migration_progress`, `migration_review_queue`, `migration_errors`, `migration_fallback_state`, `import_transactions`, `migration_daily_summary`
+
+---
+
+## TypeORM Entity Pattern
+
+### Base Entity with UUID
+
+```typescript
+// src/common/entities/base-uuid.entity.ts
+import { Column, BeforeInsert } from 'typeorm';
+import { v7 as uuidv7 } from 'uuid';
+
+export abstract class BaseUuidEntity {
+  @Column({
+    type: 'uuid',
+    unique: true,
+    nullable: false,
+    comment: 'UUID Public Identifier (ADR-019)',
+  })
+  uuid!: string;
+
+  @BeforeInsert()
+  generateUuid(): void {
+    if (!this.uuid) {
+      this.uuid = uuidv7();
+    }
+  }
+}
+```
+
+> **Note:** MariaDB native `UUID` type ทำให้ TypeORM ไม่ต้องใช้ transformer อีกต่อไป — ค่าเข้า/ออกเป็น string format เสมอ
+
+### Entity Usage Example
+
+```typescript
+// Example: correspondence.entity.ts
+import { Entity, PrimaryGeneratedColumn, Column } from 'typeorm';
+import { BaseUuidEntity } from '../../common/entities/base-uuid.entity';
+
+@Entity('correspondences')
+export class Correspondence extends BaseUuidEntity {
+  @PrimaryGeneratedColumn()
+  id!: number;
+
+  // ... existing columns
+}
+```
+
+---
+
+## API Layer Changes
+
+### URL Pattern
+
+```
+// Before (INT — vulnerable to enumeration)
+GET /api/correspondences/42
+GET /api/users/5
+
+// After (UUID — opaque identifier)
+GET /api/correspondences/019505a1-7c3e-7000-8000-abc123def456
+GET /api/users/019505a1-8b2f-7000-8000-abc123def456
+```
+
+### Controller Pattern
+
+```typescript
+@Get(':uuid')
+async findOne(@Param('uuid', ParseUUIDPipe) uuid: string) {
+  return this.service.findByUuid(uuid);
+}
+```
+
+### Service Pattern
+
+```typescript
+async findByUuid(uuid: string): Promise<CorrespondenceDto> {
+  const entity = await this.repository.findOne({
+    where: { uuid },
+  });
+  if (!entity) throw new NotFoundException();
+  return this.toDto(entity);
+}
+```
+
+### DTO Pattern — Never Expose INT ID
+
+```typescript
+export class CorrespondenceResponseDto {
+  // ✅ Expose UUID as 'id' in API response
+  @Expose({ name: 'id' })
+  uuid!: string;
+
+  // ❌ Never expose internal INT id
+  // id: number; — REMOVED from response
+
+  // ... other fields
+  // For FK references, also use UUID
+  @Expose({ name: 'project_id' })
+  projectUuid!: string;
+}
+```
+
+---
+
+## Migration SQL Script
+
+```sql
+-- =====================================================
+-- ADR-019: Add UUIDv7 columns to public-facing tables
+-- Strategy: Non-destructive — ADD COLUMN only
+-- Rollback: DROP COLUMN uuid
+-- =====================================================
+
+-- Tier 1: Core Entity Tables
+ALTER TABLE users
+  ADD COLUMN uuid UUID NOT NULL DEFAULT UUID()
+    COMMENT 'UUID Public Identifier (ADR-019)',
+  ADD UNIQUE INDEX idx_users_uuid (uuid);
+
+ALTER TABLE organizations
+  ADD COLUMN uuid UUID NOT NULL DEFAULT UUID()
+    COMMENT 'UUID Public Identifier (ADR-019)',
+  ADD UNIQUE INDEX idx_organizations_uuid (uuid);
+
+ALTER TABLE projects
+  ADD COLUMN uuid UUID NOT NULL DEFAULT UUID()
+    COMMENT 'UUID Public Identifier (ADR-019)',
+  ADD UNIQUE INDEX idx_projects_uuid (uuid);
+
+ALTER TABLE contracts
+  ADD COLUMN uuid UUID NOT NULL DEFAULT UUID()
+    COMMENT 'UUID Public Identifier (ADR-019)',
+  ADD UNIQUE INDEX idx_contracts_uuid (uuid);
+
+ALTER TABLE correspondences
+  ADD COLUMN uuid UUID NOT NULL DEFAULT UUID()
+    COMMENT 'UUID Public Identifier (ADR-019)',
+  ADD UNIQUE INDEX idx_correspondences_uuid (uuid);
+
+ALTER TABLE correspondence_revisions
+  ADD COLUMN uuid UUID NOT NULL DEFAULT UUID()
+    COMMENT 'UUID Public Identifier (ADR-019)',
+  ADD UNIQUE INDEX idx_correspondence_revisions_uuid (uuid);
+
+ALTER TABLE circulations
+  ADD COLUMN uuid UUID NOT NULL DEFAULT UUID()
+    COMMENT 'UUID Public Identifier (ADR-019)',
+  ADD UNIQUE INDEX idx_circulations_uuid (uuid);
+
+ALTER TABLE shop_drawings
+  ADD COLUMN uuid UUID NOT NULL DEFAULT UUID()
+    COMMENT 'UUID Public Identifier (ADR-019)',
+  ADD UNIQUE INDEX idx_shop_drawings_uuid (uuid);
+
+ALTER TABLE shop_drawing_revisions
+  ADD COLUMN uuid UUID NOT NULL DEFAULT UUID()
+    COMMENT 'UUID Public Identifier (ADR-019)',
+  ADD UNIQUE INDEX idx_shop_drawing_revisions_uuid (uuid);
+
+ALTER TABLE contract_drawings
+  ADD COLUMN uuid UUID NOT NULL DEFAULT UUID()
+    COMMENT 'UUID Public Identifier (ADR-019)',
+  ADD UNIQUE INDEX idx_contract_drawings_uuid (uuid);
+
+ALTER TABLE asbuilt_drawings
+  ADD COLUMN uuid UUID NOT NULL DEFAULT UUID()
+    COMMENT 'UUID Public Identifier (ADR-019)',
+  ADD UNIQUE INDEX idx_asbuilt_drawings_uuid (uuid);
+
+ALTER TABLE asbuilt_drawing_revisions
+  ADD COLUMN uuid UUID NOT NULL DEFAULT UUID()
+    COMMENT 'UUID Public Identifier (ADR-019)',
+  ADD UNIQUE INDEX idx_asbuilt_drawing_revisions_uuid (uuid);
+
+ALTER TABLE attachments
+  ADD COLUMN uuid UUID NOT NULL DEFAULT UUID()
+    COMMENT 'UUID Public Identifier (ADR-019)',
+  ADD UNIQUE INDEX idx_attachments_uuid (uuid);
+
+ALTER TABLE notifications
+  ADD COLUMN uuid UUID NOT NULL DEFAULT UUID()
+    COMMENT 'UUID Public Identifier (ADR-019)',
+  ADD INDEX idx_notifications_uuid (uuid);
+  -- Note: UNIQUE constraint on partitioned table requires uuid in partition key
+  -- Using regular INDEX instead
+```
+
+### Rollback SQL
+
+```sql
+-- Rollback: Remove UUID columns (Non-destructive reverse)
+ALTER TABLE users DROP INDEX idx_users_uuid, DROP COLUMN uuid;
+ALTER TABLE organizations DROP INDEX idx_organizations_uuid, DROP COLUMN uuid;
+ALTER TABLE projects DROP INDEX idx_projects_uuid, DROP COLUMN uuid;
+ALTER TABLE contracts DROP INDEX idx_contracts_uuid, DROP COLUMN uuid;
+ALTER TABLE correspondences DROP INDEX idx_correspondences_uuid, DROP COLUMN uuid;
+ALTER TABLE correspondence_revisions DROP INDEX idx_correspondence_revisions_uuid, DROP COLUMN uuid;
+ALTER TABLE circulations DROP INDEX idx_circulations_uuid, DROP COLUMN uuid;
+ALTER TABLE shop_drawings DROP INDEX idx_shop_drawings_uuid, DROP COLUMN uuid;
+ALTER TABLE shop_drawing_revisions DROP INDEX idx_shop_drawing_revisions_uuid, DROP COLUMN uuid;
+ALTER TABLE contract_drawings DROP INDEX idx_contract_drawings_uuid, DROP COLUMN uuid;
+ALTER TABLE asbuilt_drawings DROP INDEX idx_asbuilt_drawings_uuid, DROP COLUMN uuid;
+ALTER TABLE asbuilt_drawing_revisions DROP INDEX idx_asbuilt_drawing_revisions_uuid, DROP COLUMN uuid;
+ALTER TABLE attachments DROP INDEX idx_attachments_uuid, DROP COLUMN uuid;
+ALTER TABLE notifications DROP INDEX idx_notifications_uuid, DROP COLUMN uuid;
+```
+
+---
+
+## Storage Impact Analysis
+
+| Item | Size |
+|------|------|
+| UUID (BINARY(16) internal) per row | 16 bytes |
+| UNIQUE INDEX per row | ~16 bytes (key) + ~6 bytes (pointer) ≈ 22 bytes |
+| **Total per row** | **~38 bytes** |
+| Estimated rows (all 14 tables combined) | ~100,000 (Year 1) |
+| **Total additional storage** | **~3.8 MB** |
+| Impact on QNAP NAS | **Negligible** |
+
+---
+
+## Performance Considerations
+
+### UUIDv7 vs UUIDv4 for B-tree Index
+
+| Property | UUIDv4 | UUIDv7 |
+|----------|--------|--------|
+| Ordering | Random | Time-ordered |
+| B-tree insert | Random page splits | Sequential append |
+| Index fragmentation | High | Low |
+| Cache efficiency | Poor | Good |
+
+**UUIDv7 ถูกเลือกเพราะ Time-ordering** ทำให้ INSERT ไม่ทำให้เกิด Random Page Split บน InnoDB B-tree ซึ่งสำคัญมากสำหรับ QNAP NAS ที่มี I/O จำกัด
+
+### Query Pattern
+
+```sql
+-- Internal query (JOINs still use INT — no performance change)
+SELECT c.*, cr.*
+FROM correspondences c
+JOIN correspondence_revisions cr ON c.id = cr.correspondence_id
+WHERE c.id = 42;
+
+-- API query (UUID lookup via UNIQUE INDEX — O(log n))
+SELECT c.*, cr.*
+FROM correspondences c
+JOIN correspondence_revisions cr ON c.id = cr.correspondence_id
+WHERE c.uuid = '019505a1-7c3e-7000-8000-abc123def456';
+```
+
+---
+
+## Security Benefits
+
+| Threat | Before (INT) | After (Hybrid) |
+|--------|-------------|----------------|
+| ID Enumeration | ❌ Vulnerable (`/api/users/1,2,3...`) | ✅ Opaque UUID |
+| Record Count Leak | ❌ `id=500` reveals ~500 records | ✅ UUID reveals nothing |
+| BOLA Attack Surface | ❌ Predictable IDs | ✅ 2^122 possible values |
+| Cross-System Collision | ❌ Possible | ✅ Globally unique |
+
+---
+
+## Compatibility with Existing ADRs
+
+| ADR | Impact | Notes |
+|-----|--------|-------|
+| ADR-002 (Doc Numbering) | ✅ None | Document numbers (VARCHAR) are business identifiers, unaffected |
+| ADR-005 (Tech Stack) | ✅ Compatible | uuid npm package + MariaDB native UUID type |
+| ADR-006 (Redis Caching) | ⚠️ Minor | Cache keys should use UUID instead of INT for public-facing data |
+| ADR-009 (DB Migration) | ✅ Compatible | ADD COLUMN is a safe, non-destructive migration |
+| ADR-016 (Security) | ✅ Enhanced | Strengthens OWASP BOLA defense |
+| ADR-017 (Ollama Migration) | ✅ None | Migration tables are temporary, excluded from UUID scope |
+
+---
+
+## Transition Strategy
+
+### Phase 1: Database (Schema Change)
+- เพิ่ม `uuid UUID` column (MariaDB native type) กับ UNIQUE INDEX ใน 14 ตาราง
+- Existing rows ได้รับ UUID อัตโนมัติจาก DB DEFAULT
+
+### Phase 2: Backend (Dual-Mode)
+- เพิ่ม `uuid` field ใน TypeORM Entities
+- สร้าง `BaseUuidEntity` class
+- API รับได้ทั้ง INT และ UUID ผ่าน `FindByIdOrUuid` pattern
+- API Response รวม UUID เป็น `id` field
+
+### Phase 3: Frontend (Gradual Migration)
+- Frontend เปลี่ยนจากใช้ `id` (INT) เป็น `id` (UUID) ใน API response
+- URL parameters เปลี่ยนเป็น UUID
+- ไม่ต้อง Big-Bang migration — ค่อยๆ เปลี่ยนทีละ Module
+
+### Phase 4: Cleanup
+- ลบ INT ID จาก API Response (DTO)
+- ลบ INT-based route handlers
+- Update API Documentation
+
+---
+
+## Final Assessment
+
+| Area | Status |
+|------|--------|
+| Security | ✅ Eliminates ID enumeration |
+| Performance | ✅ No impact on internal JOINs |
+| Migration Risk | ✅ Low — ADD COLUMN only |
+| Storage Impact | ✅ Negligible (~3.8 MB) |
+| Backward Compatibility | ✅ Dual-mode transition |
+| ADR Compliance | ✅ Compatible with all existing ADRs |
+
+---
+
+*สำหรับรายละเอียดการ Implement ดูที่ Implementation Plan ใน ADR-019-implementation-plan.md*