Demo app that writes few entries to mysql using a protected status set per business logic

add_banners_protected.go

package main

import (
	"database/sql"
	"time"

	"github.com/segmentio/ksuid"
	"github.com/tjarratt/babble"

	"go.uber.org/zap"
	"gorm.io/driver/mysql"
	"gorm.io/gorm"
)

var dsn = "root:pass@tcp(127.0.0.1:3306)/sample?charset=utf8mb4&parseTime=True&loc=Local"

var babbler = babble.NewBabbler()

type Banner struct {
	BannerId        string       `gorm:"primaryKey"`
	ContentID       string       `gorm:"uniqueIndex:unique_live_banner_idx,priority=1,length:20"`
	BannerStatus    string       `gorm:"uniqueIndex:unique_live_banner_idx,priority=2,length:20"`
	IngestionStatus string       `gorm:"uniqueIndex:unique_live_banner_idx,priority=3,length:20"`
	ProtectedStatus sql.NullBool `gorm:"uniqueIndex:unique_live_banner_idx,priority=4"`
	Name            string
	CreatedAt       time.Time
	UpdatedAt       time.Time
}

func NewBanner(contentId, bannerStatus, ingestionStatus string) *Banner {
	return &Banner{
		BannerId:        ksuid.New().String(),
		ContentID:       contentId,
		BannerStatus:    bannerStatus,
		IngestionStatus: ingestionStatus,
		ProtectedStatus: sql.NullBool{},
		Name:            babbler.Babble(),
		CreatedAt:       time.Now(),
		UpdatedAt:       time.Now(),
	}
}

func (b *Banner) BeforeCreate(*gorm.DB) (err error) {
	if b.BannerStatus == b.IngestionStatus && b.BannerStatus == "LIVE" {
		b.ProtectedStatus = sql.NullBool{Bool: true, Valid: true}
	}
	return
}

func main() {
	db := setup()
	defer cleanup(db)

	// Create business queries
	db.Create(NewBanner("C1", "LIVE", "LIVE"))
	db.Create(NewBanner("C1", "LIVE", "DRAFT")) // Okay [Business]
	db.Create(NewBanner("C2", "DRAFT", "DRAFT"))
	db.Create(NewBanner("C2", "DRAFT", "DRAFT")) // Okay [Business]
	db.Create(NewBanner("C1", "LIVE", "LIVE"))   // Not Okay :| [Business]
}

func setup() *gorm.DB {
	var db *gorm.DB
	var err error
	logger, _ := zap.NewDevelopment()
	if db, err = gorm.Open(mysql.Open(dsn), &gorm.Config{}); err != nil {
		logger.Error("Couldn't connect to the database %v", zap.Error(err))
	}
	logger.Info("Database is up ", zap.String("name", db.Name()))

	// Delete rows for a fresh start and auto-populate schema
	_ = db.Migrator().DropTable(Banner{})
	_ = db.AutoMigrate(Banner{})
	return db
}

func cleanup(db *gorm.DB) {
	sqlDB, _ := db.DB()
	_ = sqlDB.Close()
}