EFMigrationsSquasher 1.0.0

EF Core Migrations Squasher

A powerful CLI tool to consolidate multiple Entity Framework Core migrations into a single migration. Perfect for cleaning up your migration history while maintaining full schema integrity and rollback capability.

Features

✨ Consolidate Migrations - Combine multiple migrations into one clean migration
🔄 Smart Down Methods - Automatically extracts or generates proper rollback operations
💾 Automatic Backup - Creates timestamped backups before any modifications
📊 SQL Scripts - Generates database update scripts for existing databases
✅ Comprehensive - Handles CreateTable, AddColumn, CreateIndex, and more
🎯 Easy to Use - Simple CLI interface with clear feedback

Installation

As a CLI Tool (Global Install)

dotnet tool install --global EFMigrationsSquasher

As a NuGet Package

dotnet add package EFMigrationsSquasher

Quick Start

Basic Usage

ef-migrations-squash --project "./MyApp/MyApp.csproj" --context "MyDbContext" --name "ConsolidatedMigration"

Options

• --project (required): Path to your .csproj file
• --context (required): Your DbContext class name
• --name (optional): Name for the new migration (default: "ConsolidatedMigration")
• --dry-run (optional): Preview changes without applying them

Example

# Preview what would happen
ef-migrations-squash --project "./Data/AppContext.csproj" --context "ApplicationDbContext" --dry-run

# Actually perform the squash
ef-migrations-squash --project "./Data/AppContext.csproj" --context "ApplicationDbContext" --name "InitialSchema"

How It Works

1. Backup Creation - Creates a timestamped backup of all migration files
2. Schema Extraction - Extracts all Up methods from existing migrations in chronological order
3. Down Method Extraction - Extracts actual Down methods or auto-generates inverse operations
4. File Cleanup - Removes old migration files
5. Consolidation - Creates a new migration with combined Up/Down logic
6. Database Script - Generates SQL for updating existing databases

Supported Operations

The tool automatically handles:

• ✅ CreateTable / DropTable
• ✅ AddColumn / DropColumn
• ✅ CreateIndex / DropIndex
• ✅ Foreign Keys and Constraints
• ✅ Custom property configurations

Example

Before (Multiple Migrations)

Migrations/
  20251122201757_init.cs
  20251122201820_AddUserAge.cs
  20251122201836_AddProductDescription.cs
  20251122201844_AddUserEmailIndex.cs

After (Consolidated)

Migrations/
  20251130223219_ConsolidatedMigration.cs (contains all operations)
  20251130223219_ConsolidatedMigration.Designer.cs
  TestDbContextModelSnapshot.cs

Important Notes

⚠️ Always backup your project first - While the tool creates automatic backups, ensure you have your own backup
⚠️ Test thoroughly - Test the consolidated migration on a development database before production
⚠️ Review generated code - Check the generated migration file to ensure it matches your schema
⚠️ Existing databases - Use the generated UpdateExistingDatabases.sql script to update migration history

For Existing Databases

After running the squash tool:

1. A file UpdateExistingDatabases.sql is generated in your Migrations folder
2. This script updates the EF Core migration history table for existing databases
3. New databases will automatically use the consolidated migration

-- Example: Run this on your existing databases
UPDATE __EFMigrationsHistory 
SET MigrationId = 'your_new_migration_id'
WHERE MigrationId IN ('old_migration_1', 'old_migration_2', ...);

Troubleshooting

"No migrations found to squash"

• Ensure your Migrations folder contains at least one migration
• Check that migration files follow the standard EF Core naming pattern

"Down method is empty"

• The tool automatically generates inverse operations from Up methods
• Review the generated Down method to ensure it's correct

Build fails after consolidation

• Check that the ModelSnapshot.cs file is valid
• Ensure all entity configurations are correct
• Review the Designer.cs file for issues

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

This project is licensed under the MIT License - see the LICENSE file for details.

Author

Created by AmirTahan80

Support

If you encounter issues or have suggestions, please open an issue on GitHub.

Made with ❤️ for the .NET community