Gorm: Postgresql: type "enum" does not exist

[liepaja]

What version of Go are you using (go version)?

1.10.1

Which database and its version are you using?

PostgreSQL 10.5

Please provide a complete runnable program to reproduce your issue. IMPORTANT

package models

import (
    "github.com/jinzhu/gorm"

    "time"
    "database/sql/driver"
)


type Project struct {
    gorm.Model
    Title    string `gorm:"unique"`
    Archived bool
    Tasks    []Task `gorm:"ForeignKey:ProjectID"`
}

func (p *Project) Archive() {
    p.Archived = true
}

func (p *Project) Restore() {
    p.Archived = false
}

type Ecosystem string

const (
    Production Ecosystem = "production"
    TestSystem Ecosystem = "testsystem"
)

func (e *Ecosystem) Scan(value interface{}) error {
    *e = Ecosystem(value.([]byte))
    return nil
}

func (e Ecosystem) Value() (driver.Value, error) {
    return string(e), nil
}


type Task struct {
    gorm.Model
    Title     string
    Ecosystem        Ecosystem `json:"ecosystem" sql:"type:ENUM('production', 'testsystem')"`
    Deadline  *time.Time `gorm:"default:null"`
    Done      bool
    ProjectID uint
}

func (t *Task) Complete() {
    t.Done = true
}

func (t *Task) Undo() {
    t.Done = false
}

// DBMigrate will create and migrate the tables, and then make the some relationships if necessary
func DBMigrate(db *gorm.DB) *gorm.DB {
    db.AutoMigrate(&Project{}, &Task{})
    db.Model(&Task{}).AddForeignKey("project_id", "projects(id)", "CASCADE", "CASCADE")
    return db
}

[mthoretton]

Could it be possible to support enum with postgres? Or to write in the doc that it's not possible to use enum with postgres? I spent quite some time trying to have it working but no success ... :(
Thanks!

[DavidLarsKetch]

While playing around with the above code snippet, I found gorm can handle ENUM struct tags if you:

1. Manually create the ecosystem ENUM type:
   go db.Exec("CREATE TYPE ecosystem AS ENUM('production', 'testsystem');")
2. Manually create the tasks table:
   go db.Exec("CREATE TABLE tasks (id integer PRIMARY KEY, title text, ecosystem ecosystem, ...);")

Essentially, AutoMigrate appears to be the culprit.

[jinzhu]

Manually create the ecosystem ENUM type

Yes

Manually create the tasks table

Not necessary, just set column's type to the type you created

[jinzhu]

https://github.com/go-gorm/gorm/issues/1978#issuecomment-476673540