Migrate IndexedDB to Dexie.js

[Copilot]

Migration Plan: IndexedDB to Dexie.js

• Explore repository structure and understand current implementation
• Verify build and test setup works
• Create Dexie database schema definition
• Migrate database initialization from raw IndexedDB to Dexie
• Migrate saveConfigToDB function to use Dexie
• Migrate loadConfigFromDB function to use Dexie
• Migrate saveImageToDB function to use Dexie
• Migrate deleteImageFromDB function to use Dexie
• Migrate clearDB function to use Dexie
• Keep utility functions (blobToBase64, base64ToBlob, validateContestData, exportConfig, importConfig) unchanged
• Run lint, build, and tests to verify changes
• Run security checks (CodeQL)
• Fix data compatibility issue - preserve existing data structure
• Complete migration

Summary

✅ Migration Complete! Successfully migrated the project's IndexedDB implementation to Dexie.js with full backward compatibility.

Key Changes

1. Created Dexie database class - Defined CnoiDatabase extending Dexie with two object stores:

   • config store for storing contest configuration (using out-of-line keys to match original structure)
   • images store for storing image blobs with uuid as inline key

2. Simplified database operations:

   • Replaced verbose promise-based IndexedDB transactions with Dexie's clean async/await API
   • Removed manual database connection management (open/close calls)
   • Used Dexie's built-in methods: put(), get(), bulkGet(), delete(), clear()
   • Improved performance with bulkGet() for loading multiple images

3. Maintained 100% backward compatibility:

   • Same database name: "cnoi-statement-generator"
   • Same version: 1
   • Same data structure - config store uses out-of-line keys (empty string in schema) to match the original IndexedDB format
   • All function signatures remain unchanged
   • Existing user data will be preserved when reopening the website

Technical Details

The config store schema uses an empty string config: "" which tells Dexie to use out-of-line keys (keys stored separately from the object). This exactly matches the original IndexedDB implementation where we stored data as store.put(storedData, "current").

Validation

✅ All linting checks pass
✅ Build succeeds
✅ All 144 tests pass
✅ CodeQL security scan - 0 vulnerabilities found
✅ Only 1 file modified (src/utils/indexedDBUtils.ts)
✅ User data compatibility verified - existing data will load correctly

Original prompt

将项目index DB迁移到 dexie.js

[Chronological Review: The conversation began with the user requesting to migrate the project's IndexedDB to Dexie.js. The user has been working on the file located at /home/mrpython/Desktop/cnoi-statement-generator/src/utils/indexedDBUtils.ts, indicating a focus on updating the database handling to utilize the Dexie.js library.]

[Intent Mapping: The explicit user request was "将项目index DB迁移到 dexie.js" (migrate the project's IndexedDB to Dexie.js). The user aims to modernize the database management within their project.]

[Technical Inventory: The conversation involves the following technologies:

• Dexie.js: A wrapper for IndexedDB that simplifies database operations.
• IndexedDB: The original database technology being used in the project.
• TypeScript: The language used in the project, as indicated by the file extension .ts.]

[Code Archaeology: The file discussed is indexedDBUtils.ts, which likely contains functions and logic related to the current IndexedDB implementation that needs to be modified to work with Dexie.js.]

[Progress Assessment: The user has not yet indicated any completed tasks regarding the migration, as the conversation has primarily focused on the initial request.]

[Context Validation: All critical information for continuation is captured, including the user's goal of migrating to Dexie.js and the specific file being worked on.]

[Recent Commands Analysis: The user has not executed any specific commands or tools in this conversation, but the focus has been on the request to migrate the database. The immediate pre-summarization state was the user actively discussing the migration of IndexedDB to Dexie.js.]

1. Conversation Overview: - Primary Objectives: The user explicitly requested, "将项目index DB迁移到 dexie.js" (migrate the project's IndexedDB to Dexie.js). - Session Context: The conversation has revolved around the user's intention to modernize the database handling in their project by transitioning from IndexedDB to Dexie.js, with a focus on the file indexedDBUtils.ts. - User Intent Evolution: The user's needs have remained consistent, focusing on the migration task without any indication of shifting priorities.

2. Technical Foundation:

• Dexie.js: A library that simplifies working with IndexedDB, intended to replace the current IndexedDB implementation.
• IndexedDB: The original database technology being used in the project.
• TypeScript: The programming language used for the project, as indicated by the file extension.

3. Codebase Status:

• File Name: indexedDBUtils.ts
• Purpose: This file is crucial for managing the IndexedDB operations within the project.
• Current State: The file is currently being prepared for migration to Dexie.js, but no specific changes have been documented yet.
• Key Code Segments: Specific functions or classes within this file have not been detailed in the conversation.
• Dependencies: The file's functionality is tied to the current IndexedDB implementation, which will need to be updated to work with Dexie.js.

4. Problem Resolution:

• Issues Encountered: No specific technical problems have been discussed yet.
• Solutions Implemented: No solutions have been documented as the migration process has not yet begun.
• Debugging Context: There are no ongoing troubleshooting efforts mentioned.
• Lessons Learned: No insights or patterns have been discovered yet.

5. Progress Tracking:

• Completed Tasks: No tasks have been completed regarding the migration.
• Partially Complete Work: The migration task is in the planning phase, with the user focused on the initial request.
• Validated Outcomes: No features or code have been confirmed working through testing.

6. Active Work State:

• Current Focus: The user is focused on migrating the IndexedDB to Dexie.js.
• Recent Context: The last few exchanges have centered around the user's request for migration and the file being worked on.
• Working Code: No specific code snippets have been modified or discussed recently.
• Immediate Context: The user was addressing the migration of IndexedDB to Dexie.js before the summary was triggered.

7. Recent Operations:

• Last Agent Commands: No specific commands were executed by the agent.
• Tool Results Summary: There are no tool results to summarize as the conversation has been focused on the user's request.
• Pre-Summary State: The agent was actively discussing the migration of IndexedDB to Dexie.js.
• Operation Context: The conversation's focus on migrating to Dexie.js aligns with the user's goal of modernizing their database management.

8. Continuation Plan:

• Pending Task 1: The next steps involve implementing the migration of IndexedDB to Dexie.js in the indexedDBUtils.ts file.
• Pending Task 2: The user may need to explore Dexie.js documentation for specific implementation details.
• Priority Information: The migration task is the most urgent and logically sequential.
• Next Action: The immediate next step is to b...

Created from VS Code via the GitHub Pull Request extension.

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Project	Deployment	Preview	Comments	Updated (UTC)
cnoi-statement-generator	Ready	Preview	Comment	Nov 13, 2025 9:38am

[cloudflare-workers-and-pages]

Deploying cnoi-statement-generator with    Cloudflare Pages

Latest commit:	523c3be
Status:	✅  Deploy successful!
Preview URL:	https://6f0df17b.cnoi-statement-generator.pages.dev
Branch Preview URL:	https://copilot-vscode1763024263855.cnoi-statement-generator.pages.dev

View logs

[Mr-Python-in-China]

@copilot 这样再次打开网站时原有的数据会丢失吗

[Copilot]

@copilot 这样再次打开网站时原有的数据会丢失吗

不会丢失。我已经修复了数据兼容性问题 (commit 523c3be)。

现在 config store 使用与原始 IndexedDB 相同的数据结构（out-of-line keys），确保现有用户数据在重新打开网站时能够正常加载。数据库名称、版本号和存储结构都保持不变。

[Mr-Python-in-China]

@copilot 在后续的开发中，我想升级数据库版本时，我应该怎么做

[Copilot]

@copilot 在后续的开发中，我想升级数据库版本时，我应该怎么做

使用 Dexie 的版本升级系统很简单。在 CnoiDatabase 类的构造函数中添加新版本即可：

constructor() {
  super("cnoi-statement-generator");
  
  // 版本 1 - 当前版本
  this.version(1).stores({
    config: "",
    images: "uuid",
  });
  
  // 版本 2 - 添加新表或修改索引
  this.version(2).stores({
    config: "",
    images: "uuid",
    newTable: "id, name", // 新增表
  }).upgrade(tx => {
    // 可选：数据迁移逻辑
    return tx.table("images").toCollection().modify(image => {
      // 修改现有数据
    });
  });
}

Dexie 会自动：

1. 检测用户当前的数据库版本
2. 按顺序执行所需的升级步骤
3. 保留所有现有数据

文档参考: https://dexie.org/docs/Tutorial/Design#database-versioning