GORM returns empty string from already-existing table

Question

I have a table in a Postgres db (artwork_migrate_era)

I'm using GORM. I find that in order for my model to work with an already existing table, I need to use the TableName() method like so:

type Era struct {
    id            int       `json:"id"`
    era_name      string    `json:"era_name"`
    last_modified time.Time `json:"last_modified"`
}

// allows to use gorm model with already-existing table in db: https://stackoverflow.com/questions/66318666/golang-gorm-how-to-create-a-model-for-an-existing-table

func (Era) TableName() string {
    return "artwork_migrate_era"
}

I'm also using GIN to make requests:

func main() {
    dsn := "...db_credentials..."
    db, err := gorm.Open(postgres.Open(dsn), &gorm.Config{})
    if err != nil {
        panic("failed to connect to db")
    }

    db.AutoMigrate(&Era{})

    router := gin.Default()
    router.GET("/era/:id", func(c *gin.Context) {

        id := c.Param("id")
        var era Era
        db.Where("id = ?", id).Find(&era)

        c.JSON(http.StatusOK, gin.H{
            "Era": era.era_name,
        })
    })

    router.Run("localhost:8080")

}

when I make the following request: curl localhost:8080/era/4

I get get the following response: {"Era":""}

Am I just missing something obvious?

Answer 1

db.Where("id = ?", id).Find(&era) would not be able to map the data to your struct export all the members of your struct by making the first letter Capital