pgStuff.go

// Run "createdb pgstuff" first
package main

import(
  "fmt"
  "gorm.io/driver/postgres"
  "gorm.io/gorm"
  "time"
)

type Model struct {
  ID        uint      `gorm:"primaryKey"`
  CreatedAt time.Time `json:"created_at,omitempty"`
  UpdatedAt time.Time `json:"updated_at,omitempty"`
}

type Service struct {
  Model
  Owner            string
  Name             string           `gorm:"not null; index"`
  PeerDependencies []PeerDependency `gorm:"many2many:peer_memberships"`
}

type PeerDependency struct {
  Model
  Name     string
  Owner    string
  Services []Service `gorm:"many2many:peer_memberships"`
}

func main() {
  conf := &gorm.Config{
    PrepareStmt:	false,
    FullSaveAssociations: false,
    SkipDefaultTransaction: true,
  }

  pconf := postgres.Config{
    DSN: "user=dberger password=dberger dbname=pgstuff",
    PreferSimpleProtocol: true,
  }

  db, err := gorm.Open(postgres.New(pconf), conf)

  if err != nil {
    panic("failed to connect database")
  }

  db.AutoMigrate(&Service{}, &PeerDependency{})

  pd1 := PeerDependency{
    Name: "databases",
    Owner: "[email protected]",
    Services: []Service{
      {Name: "mysql", Owner: "[email protected]"},
      {Name: "postgres", Owner: "[email protected]"},
    },
  }

  db.Create(&pd1)

  var pd PeerDependency
  db.Debug().Preload("Services").First(&pd)
  fmt.Printf("PD:\t %v\n\n", pd)
  fmt.Printf("SERVICES:\t %v\n\n", pd.Services)

  var service Service
  db.Preload("PeerDependencies").First(&service)
  fmt.Printf("SERVICE 1:\t %v\n\n", service)
}