---

name: database-migrator description: Schema version control, migration script generation, rollback management version: 1.0.0 tags: [database, migration, schema, versioning, sql]

Database Migrator Skill

Purpose

The Database Migrator Skill manages database schema evolution through version-controlled migrations. It generates migration scripts, tracks schema versions, validates migrations, and provides safe rollback capabilities.

Key Capabilities:

• Auto-generate migration scripts from schema changes
• Version control for database schemas
• Safe migration execution with validation
• Rollback management
• Multi-database support (PostgreSQL, MySQL, SQLite)
• Migration conflict detection

Target Token Savings: 70% (from ~2300 tokens to ~690 tokens)

When to Use

• Creating database schema changes
• Deploying schema updates
• Rolling back migrations
• Syncing development/production schemas
• Generating migration scripts
• Validating schema compatibility

Operations

1. generate-migration

Generates migration script from schema diff.

2. apply-migration

Applies pending migrations to database.

3. rollback

Rolls back last migration.

4. validate

Validates migration scripts for safety.

5. status

Shows current migration status.

Scripts

Copy# Generate migration
python ~/.claude/skills/database-migrator/scripts/main.py \
  --operation generate-migration \
  --name add_users_table

# Apply migrations
python ~/.claude/skills/database-migrator/scripts/main.py \
  --operation apply-migration \
  --db-url postgresql://localhost/mydb

# Rollback last migration
python ~/.claude/skills/database-migrator/scripts/main.py \
  --operation rollback \
  --db-url postgresql://localhost/mydb

# Check migration status
python ~/.claude/skills/database-migrator/scripts/main.py \
  --operation status \
  --db-url postgresql://localhost/mydb

Configuration

Copy{
  "database-migrator": {
    "migrations_dir": "./migrations",
    "database_url": "postgresql://localhost/mydb",
    "auto_apply": false,
    "validate_before_apply": true,
    "create_backup": true,
    "rollback_on_error": true
  }
}

Examples

Example 1: Generate Migration

Copypython ~/.claude/skills/database-migrator/scripts/main.py \
  --operation generate-migration \
  --name add_email_column

Output:

Copy{
  "success": true,
  "operation": "generate-migration",
  "migration_file": "migrations/001_add_email_column.sql",
  "version": "001",
  "execution_time_ms": 23
}

Example 2: Apply Migrations

Copypython ~/.claude/skills/database-migrator/scripts/main.py \
  --operation apply-migration \
  --db-url postgresql://localhost/mydb

Output:

Copy{
  "success": true,
  "operation": "apply-migration",
  "migrations_applied": 3,
  "current_version": "003",
  "execution_time_ms": 456
}

Example 3: Rollback Migration

Copypython ~/.claude/skills/database-migrator/scripts/main.py \
  --operation rollback \
  --db-url postgresql://localhost/mydb

Output:

Copy{
  "success": true,
  "operation": "rollback",
  "rolled_back": "003_add_index",
  "current_version": "002",
  "execution_time_ms": 234
}

Example 4: Migration Status

Copypython ~/.claude/skills/database-migrator/scripts/main.py \
  --operation status \
  --db-url postgresql://localhost/mydb

Output:

Copy{
  "success": true,
  "operation": "status",
  "current_version": "003",
  "pending_migrations": 2,
  "applied_migrations": 3,
  "execution_time_ms": 12
}

Token Economics

Without Skill: ~2300 tokens With Skill: ~690 tokens (70% savings)

Success Metrics

• Execution time: <50ms for generation
• Migration success rate: >99.9%
• Zero data loss in rollbacks
• Schema validation: 100% accuracy

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Database Migrator Skill v1.0.0 - Safe database schema evolution