gorm-custom-data-types

What problem does it solve?

Many Go types cannot be directly mapped to database column representations, making it difficult to store structured, encrypted, or dialect-specific values reliably; this Skill provides patterns and interfaces to convert complex Go values into database-compatible formats for GORM models.

Core Features & Use Cases

• Scanner and Valuer Integration: Implement sql.Scanner and driver.Valuer to control how values are read from and written to the database.
• Dialect-Specific Types: Define GormDBDataType to return database-specific column types for migrations across MySQL, Postgres, SQLite, and others.
• SQL Expression Support: Provide GormValue/GormValuer implementations to persist values using SQL expressions or database functions, useful for spatial types or context-aware encryption.
• Use Case: Store JSON objects as JSONB on Postgres, JSON on MySQL, or TEXT on SQLite while preserving queryability and migration correctness.

Quick Start

Create a GORM model field that implements Scanner and Valuer, implement GormDBDataType for your target dialect, and run AutoMigrate to verify the generated column type.