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Models

Models are Go structs that map to database tables using GORM. They live in app/models/.

Generating a model

catuaba g model Product name:string price:float description:text active:boolean

This creates two files:

  • app/models/product.go — the Go struct
  • database/migrations/<timestamp>_create_products.up.sql — SQL to create the table
  • database/migrations/<timestamp>_create_products.down.sql — SQL to drop the table

Generated code

package models

import "gorm.io/gorm"

type Product struct {
    gorm.Model
    Name        string  `json:"name"`
    Price       float64 `json:"price"`
    Description string  `json:"description"`
    Active      bool    `json:"active"`
}

gorm.Model embeds ID, CreatedAt, UpdatedAt, and DeletedAt (soft delete).

Field types

CLI type Go type SQL type Example
string string VARCHAR(255) name:string
text string TEXT bio:text
integer int INTEGER age:integer
float float64 REAL price:float
boolean bool BOOLEAN active:boolean
datetime time.Time TIMESTAMP published_at:datetime

Querying

Models are queried through the database.DB global (a *gorm.DB instance):

// Find all
var products []models.Product
database.DB.Find(&products)

// Find by ID
var product models.Product
database.DB.First(&product, 1)

// Where clause
database.DB.Where("active = ?", true).Find(&products)

// Pagination
database.DB.Offset(0).Limit(20).Find(&products)

// Count
var count int64
database.DB.Model(&models.Product{}).Count(&count)

// Create
product := models.Product{Name: "Widget", Price: 9.99}
database.DB.Create(&product)

// Update
database.DB.Save(&product)

// Delete (soft delete — sets deleted_at)
database.DB.Delete(&product)

Relationships

GORM supports all standard relationships. Add them manually to your model:

// app/models/post.go
type Post struct {
    gorm.Model
    Title      string    `json:"title"`
    Body       string    `json:"body"`
    CategoryID uint      `json:"category_id"`
    Category   Category  `json:"category" gorm:"foreignKey:CategoryID"`
    Tags       []Tag     `json:"tags" gorm:"many2many:post_tags;"`
}

// app/models/category.go
type Category struct {
    gorm.Model
    Name  string `json:"name"`
    Posts []Post `json:"posts"`
}

Eager-loading:

database.DB.Preload("Category").Preload("Tags").Find(&posts)

Migrations

Catuaba uses raw SQL migrations (not AutoMigrate). Each model generator creates paired up/down files:

-- database/migrations/20240101120000_create_products.up.sql
CREATE TABLE IF NOT EXISTS products (
    id INTEGER PRIMARY KEY AUTOINCREMENT,
    name VARCHAR(255) NOT NULL DEFAULT '',
    price REAL NOT NULL DEFAULT 0,
    description TEXT NOT NULL DEFAULT '',
    active BOOLEAN NOT NULL DEFAULT 0,
    created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
    deleted_at TIMESTAMP
);

-- database/migrations/20240101120000_create_products.down.sql
DROP TABLE IF EXISTS products;

Run migrations:

catuaba db migrate     # Run all pending
catuaba db rollback    # Rollback last
catuaba db status      # Show status

Create a manual migration (e.g., adding an index):

catuaba g migration add_index_to_products_name

Then edit the generated SQL files manually.

Learn more