entity_repository.go

package entity_repository

import "gorm.io/gorm"

type EntityRepository[e any] struct {
	db *gorm.DB
}

func NewRepository[e any](db *gorm.DB) *EntityRepository[e] {
	return &EntityRepository[e]{
		db: db,
	}
}

func (r *EntityRepository[e]) GetAll() ([]*e, error) {
	var entities []*e
	result := r.db.Find(&entities)
	if result.Error != nil {
		return nil, result.Error
	}
	if len(entities) == 0 {
		// if there are no entities, return empty slice instead of nil...
		return make([]*e, 0), nil
	}
	return entities, nil
}

func (r *EntityRepository[e]) GetByID(id uint) (*e, error) {
	var entity e
	result := r.db.First(&entity, id)
	if result.Error != nil {
		return nil, result.Error
	}
	return &entity, nil
}

func (r *EntityRepository[e]) Create(entity *e) (*e, error) {
	result := r.db.Create(entity)
	if result.Error != nil {
		return entity, result.Error
	}
	return entity, nil
}

func (r *EntityRepository[e]) Update(entity *e) (*e, error) {
	result := r.db.Save(entity)
	if result.Error != nil {
		return entity, result.Error
	}
	return entity, nil
}

func (r *EntityRepository[e]) Delete(entity *e) error {
	result := r.db.Delete(entity)
	if result.Error != nil {
		return result.Error
	}
	return nil
}