pgsql-jellyfin/docs/GENERATE_POSTGRESQL_MIGRATIONS.md

Generate PostgreSQL Migrations from SQLite

This script generates PostgreSQL migrations that match the SQLite migration schema.

Prerequisites

• .NET SDK installed
• dotnet-ef tools installed: dotnet tool install --global dotnet-ef
• PostgreSQL database running (for testing)

Step 1: Initial Migration Generation

Since the DbContext model is shared between SQLite and PostgreSQL providers, we can generate PostgreSQL migrations directly from the model:

# Navigate to PostgreSQL provider project
cd E:\Projects\pgsql-jellyfin\src\Jellyfin.Database\Jellyfin.Database.Providers.Postgres

# Generate the initial migration (creates all tables matching current DbContext)
dotnet ef migrations add InitialCreate --context JellyfinDbContext --output-dir Migrations

# This will create migration files matching the current schema

Step 2: Verify Generated Migration

The generated migration should include all tables:

• ActivityLogs
• Users, Permissions, Preferences
• Devices, DeviceOptions
• DisplayPreferences, ItemDisplayPreferences, CustomItemDisplayPreferences
• ImageInfos
• TrickplayInfos
• MediaSegments
• BaseItems, AncestorIds, AttachmentStreamInfos
• Chapters, ItemValues, ItemValuesMap
• MediaStreamInfos, UserData
• And more...

Step 3: Apply Migration (Test)

# Test on a PostgreSQL database
dotnet ef database update --context JellyfinDbContext --connection "Host=localhost;Database=jellyfin_test;Username=jellyfin;Password=test"

Alternative: Manual Migration Copying (Not Recommended)

If you need to maintain separate migrations per provider (not typical for EF Core):

1. Copy SQLite migration structure
2. Replace SQLite-specific code with PostgreSQL equivalents:
   • .Annotation("Sqlite:Autoincrement", true) → .Annotation("Npgsql:ValueGenerationStrategy", NpgsqlValueGenerationStrategy.IdentityByDefaultColumn)
   • type: "TEXT" → type: "text" or appropriate PostgreSQL type
   • type: "INTEGER" → type: "integer" or type: "bigint"
   • type: "REAL" → type: "real" or type: "double precision"

Why Single Migration is Better

EF Core migrations are provider-agnostic at the model level. The same migration can target different databases:

• The migration C# code uses MigrationBuilder API (database-agnostic)
• EF Core generates database-specific SQL at runtime
• One migration file works for SQLite, PostgreSQL, MySQL, etc.

The difference is in the migration assembly location:

• SQLite migrations: Jellyfin.Database.Providers.Sqlite assembly
• PostgreSQL migrations: Jellyfin.Database.Providers.Postgres assembly

Each provider has its own migration history.

Recommended Approach

Use the InitialCreate migration generated from the current DbContext model. This will:

• ✅ Match the current schema exactly
• ✅ Be PostgreSQL-optimized
• ✅ Include all tables, indexes, and constraints
• ✅ Work with the migration system
• ✅ Be maintainable going forward

Post-Generation Steps

After generating the initial migration:

1. Review the generated code - ensure all tables are included
2. Test on clean database - verify schema creation works
3. Compare with SQLite schema - ensure parity
4. Commit to source control - save the migration files
5. Document any PostgreSQL-specific customizations

Future Migrations

For new schema changes:

1. Update the JellyfinDbContext model
2. Generate migration for BOTH providers:

   # SQLite
   cd src\Jellyfin.Database\Jellyfin.Database.Providers.Sqlite
   dotnet ef migrations add YourMigrationName --context JellyfinDbContext
   
   # PostgreSQL
   cd ..\Jellyfin.Database.Providers.Postgres
   dotnet ef migrations add YourMigrationName --context JellyfinDbContext
   

Execution

To execute this script:

# Run the generation command
.\Generate-PostgreSQLMigrations.ps1