# CS0006 Error Fix - SQLite References Removal

**Error:** CS0006 - Metadata file could not be found  
**Root Cause:** Code still references SQLite types after removing SQLite dependencies  
**Status:** ✅ Partially Fixed - Migration code needs special handling

---

## Errors Found and Fixed

### ✅ Fixed Issues

1. **Jellyfin.Server.Implementations\Extensions\ServiceCollectionExtensions.cs**
   - ❌ Line 16: `using Jellyfin.Database.Providers.Sqlite;` → **REMOVED**
   - ❌ Line 31: `yield return typeof(SqliteDatabaseProvider);` → **REMOVED**
   
2. **Emby.Server.Implementations\Data\SqliteExtensions.cs**
   - ❌ Entire file → **DELETED** (not used anywhere)

---

## ⚠️ Remaining Issues - Migration Routines

These files in `Jellyfin.Server\Migrations\Routines\` still reference SQLite:

1. `MigrateActivityLogDb.cs`
2. `MigrateAuthenticationDb.cs`
3. `MigrateDisplayPreferencesDb.cs`
4. `MigrateLibraryDb.cs`
5. `MigrateLibraryDbCompatibilityCheck.cs`
6. `MigrateLibraryUserData.cs`
7. `MigrateUserDb.cs`
8. `RemoveDuplicateExtras.cs`
9. `ReseedFolderFlag.cs`

**Why they exist:** These are migration routines to migrate FROM SQLite TO PostgreSQL

---

## Decision: What to Do About Migrations?

### Option 1: Keep SQLite Package for Migrations Only ✅ RECOMMENDED

**Pros:**
- Users can still migrate from SQLite
- No breaking changes
- SQLite DLLs only used during migration

**Implementation:**
1. Add `Microsoft.Data.Sqlite` back to `Jellyfin.Server.csproj` ONLY
2. Migrations can run when needed
3. SQLite provider project still removed (no SQLite for runtime database)

**Result:** SQLite DLLs in deployment, but ONLY for migration support

---

### Option 2: Remove Migration Code Entirely ❌ NOT RECOMMENDED

**Pros:**
- No SQLite dependencies at all
- Smaller deployment

**Cons:**
- Users CANNOT migrate from SQLite
- Breaking change for existing users
- Requires manual migration

---

### Option 3: Make Migrations Optional Plugin

**Pros:**
- Clean deployment (no SQLite)
- Migration still possible via plugin

**Cons:**
- Complex to implement
- Extra step for users

---

## ✅ RECOMMENDED SOLUTION

**Add SQLite package ONLY to Jellyfin.Server for migration support**

This allows:
- Migration FROM SQLite TO PostgreSQL
- No SQLite as runtime database
- Minimal impact on deployment size (~5MB)

---

## Implementation Steps

### Step 1: Add Microsoft.Data.Sqlite to Jellyfin.Server

```xml
<!-- In Jellyfin.Server/Jellyfin.Server.csproj -->
<ItemGroup>
  <!-- SQLite package for migration routines only -->
  <PackageReference Include="Microsoft.Data.Sqlite" />
</ItemGroup>
```

### Step 2: Rebuild

```powershell
dotnet clean
dotnet build --configuration Release
```

### Step 3: Verify

- ✅ Build succeeds
- ✅ SQLite DLLs present for migrations
- ✅ SQLite NOT used as runtime database
- ✅ Only PostgreSQL provider in service collection

---

## Alternative: Remove Migrations

If you want ZERO SQLite dependencies:

### Step 1: Delete Migration Files

```powershell
Remove-Item "Jellyfin.Server\Migrations\Routines\*" -Recurse
```

### Step 2: Document Migration Process

Create `docs/SQLITE_TO_POSTGRES_MANUAL_MIGRATION.md` with manual steps

### Step 3: Update README

```markdown
**Note:** This build does NOT support migrating from SQLite.
Use the official Jellyfin tools to migrate first, then switch to this version.
```

---

## Size Impact

### With Migration Support (Recommended)
```
SQLite DLLs:
- Microsoft.Data.Sqlite.dll: ~400 KB
- SQLitePCLRaw.*.dll: ~2-5 MB
Total: ~5-7 MB added
```

### Without Migration Support
```
Total: 0 MB
But users cannot migrate from SQLite
```

---

## Current Status

✅ **Fixed:**
- ServiceCollectionExtensions.cs (provider registration)
- SqliteExtensions.cs (deleted)
- Package reference removed from Emby.Server.Implementations

❌ **Still has SQLite references:**
- 9 migration routine files in Jellyfin.Server

---

## Next Steps (Choose One)

### Approach A: Keep Migrations (Recommended) ✅

```powershell
# Add package to Jellyfin.Server.csproj
# Then rebuild
dotnet build --configuration Release
```

### Approach B: Remove Migrations

```powershell
# Delete migration routines
Remove-Item "E:\Projects\pgsql-jellyfin\Jellyfin.Server\Migrations\Routines\Migrate*.cs"
Remove-Item "E:\Projects\pgsql-jellyfin\Jellyfin.Server\Migrations\Routines\Reseed*.cs"
Remove-Item "E:\Projects\pgsql-jellyfin\Jellyfin.Server\Migrations\Routines\Remove*.cs"

# Rebuild
dotnet build --configuration Release
```

---

## Recommendation

**✅ Use Approach A: Keep SQLite for migrations**

**Why:**
1. Users can still migrate their data
2. Minimal size impact (~5MB)
3. One-time cost (migrations run once)
4. No breaking changes for users transitioning from SQLite

**When to use Approach B:**
- You're distributing to NEW users only
- No one needs SQLite migration
- You want absolutely zero SQLite code

---

## Summary

**Problem:** CS0006 error due to SQLite references  
**Root Cause:** Migration code needs SQLite  
**Solution:** Add `Microsoft.Data.Sqlite` to `Jellyfin.Server.csproj` for migration support  
**Result:** Build succeeds, migrations work, no SQLite as runtime database  

---

**What do you prefer?**
1. Keep migrations (add SQLite package back for migrations)
2. Remove migrations (delete migration files, zero SQLite)

Let me know and I'll implement it!