Database Migration Review Findings

Database Migration Review Findings | Generated by AI

Home 2026.04

Here’s the migration review:

🦞 CI3→CI4 Migration Review

Overall: Good foundation, but the app is still broken at the database layer.

✅ What’s Done Well

Container stack is solid — PHP 8.5-FPM + nginx + MySQL 5.7 + Redis, all running and communicating on Docker internal networking
BaseController is properly migrated — CI4-style HTTP request methods, response helpers, session handling
BaseDao exists with SET NAMES utf8mb4 initialization
WeChatClient is clean CI4-compatible code (no get_instance() dependencies)
CI4 public/index.php is correct with proper Boot::bootWeb() entry point
Constants/env are populated with all the real keys (WeChat, Qiniu, RTMP, DB credentials)

🚨 Critical Blockers (App = HTTP 500)

1. Database connection is completely broken (THE root cause right now)

mysqli_sql_exception: No such file or directory

app/Config/Database.php has hostname: 'localhost' hardcoded — inside the container, MySQL is on the database host, not a socket file. The env vars (DB_HOST=database, DB_USER=root, DB_PASS=WeImg4096) are injected into PHP but never read by the Database.php config. It needs to pull from $_ENV or env().

2. Every controller still uses CI3-style $this->load (~60+ occurrences across ~20 controllers):

$this->load->library(JSSDK::class);
$this->load->model(UserDao::class);
$this->load->library(WeChatPlatform::class);

These need to become constructor-injected or service-locator resolved in CI4.

3. Libraries directory is almost empty — WeChatClient.php is there, but:

JSSDK.php — missing, still CI3
WeChatPlatform.php — missing, still CI3
Pay.php, Sms.php, wx/WxPay.php, wx/WxPayCallback.php — all missing CI4 versions

4. No REST_Controller — checking the grep output showed no REST_Controller references, which is good (may have already been handled), but need to confirm all API controllers work.

📋 Remaining Work (Priority Order)

Priority	Task	Effort
🔴 P0	Fix `Database.php` to read env vars (`hostname => env('DB_HOST', 'database')`)	5 min
🔴 P0	Fix `BaseController` constructor — remove eager `new UserDao()` that triggers DB on every request	10 min
🟡 P1	Rewrite `JSSDK.php` for CI4 (`Services::curlrequest()`, `Services::cache()`)	~1 hr
🟡 P1	Create CI4 `WeChatPlatform` library	~1 hr
🟡 P1	Fix all 20 controllers with `$this->load->model/library` → proper DI	~2 hr
🟢 P2	Verify Pay, Sms, WxPay libraries	~1 hr
🟢 P2	End-to-end test all major routes	~1 hr

💡 The Fastest Path to HTTP 200

Fix Database.php env reading → might get to a different error (rather than DB fail)
Delay UserDao instantiation in BaseController → lazy init or remove from constructor
Fix JSSDK.php → that alone might unblock most WeChat routes
Then tackle the $this->load refactor controller by controller

Want me to start fixing from the top?

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