Migration Writing

Purpose

Write database migrations that safely modify schema while preserving data integrity.

When to Use

• New table/column additions

• Schema modifications

• Index changes

• Data transformations

Process

• Plan migration

• Write forward migration

• Write rollback (if needed)

• Test in development

• Test with production-like data

StudyAbroad-Specific Considerations

• Always have rollback plan

• Test with realistic data volumes

• Consider GDPR (soft deletes)

• Handle production data carefully

Examples

// prisma/migrations/20240115_add_virus_scan/migration.sql

-- Add virus scan fields to documents table ALTER TABLE documents ADD COLUMN virus_scan_status VARCHAR(20) DEFAULT 'pending', ADD COLUMN virus_scan_at TIMESTAMP, ADD COLUMN virus_scan_result JSONB;

-- Create index for pending scans CREATE INDEX idx_documents_scan_pending ON documents (virus_scan_status) WHERE virus_scan_status = 'pending';