db.Model(&Usertable).Create(data): How to pass the correct tablename?

Question

I am trying to insert a row into a table defined as a model. Below is the relevant code snippets:

Package Structure:

gorm
|- server
   |- insertRow.go
|- pkg
   |- models
      |- mytable.go
   |- database
      | - connectdb.go

mytable.go:

package models

type Usertable struct {
    Firstname    string `gorm:"column:firstname"`
    Lastname  string `gorm:"column:lastname"`
}

func (fmap *Usertable) TableName() string { return "usertable" }

insertRow.go

package main
import (
        "fmt"
       "gorm/pkg/models"
        "gorm/pkg/database"
)

func  main() {
  params := map[string]interface{} {
        "Firstname" : "MyFirstName",
        "Lastname" : "LastName" ,
 }
        db, _ := database.NewStorage("postgres", "testdb")

        var user models.Usertable

        err := db.DB.Debug().Model(&user).Create(params)
        if err != nil {
                fmt.Println("Error :=", err)
        } else {
                fmt.Println("Success")
        }

}

Table Definition:

testdb=# \d+ usertable
                                 Table "public.usertable"
  Column   | Type | Collation | Nullable | Default | Storage  | Stats target | Description
-----------+------+-----------+----------+---------+----------+--------------+-------------
 firstname | text |           |          |         | extended |              |
 lastname  | text |           |          |         | extended |              |

Executing the insertRow.go gives the following error:

(/root/gorm/cloudOps/server/testDB/insertRow.go:17)
[2023-09-23 23:51:26]  pq: zero-length delimited identifier at or near """"

(/root/gorm/cloudOps/server/testDB/insertRow.go:17)
[2023-09-23 23:51:26]  [0.45ms]  **INSERT INTO "" DEFAULT VALUES RETURNING "".***
[0 rows affected or returned ]
Error := &{{{0 0} 0 0 {{} 0} {{} 0}} map[Firstname:MyFirstName Lastname:LastName] pq: zero-length delimited identifier at or near """" 0 0xc0000a4b60 false 2 {0xc0001a3d60} 0xc0001e8420 {{0 0} {[] {} 0xc00021cc20} map[] 0} 0xc0000a4c30 <nil> 0xc0000a2c78 false <nil>}

It seems that the tablename in the insert command is blank, please let me know what is wrong with my insert command and how to pass the right tablename to the Create call.

I tried this also with the same result:

    package main
import (
    "fmt"
//       "gorm/pkg/models"
    "gorm/pkg/database"
    "gorm.io/gorm"
)

type Usertable struct {
    gorm.Model
    Firstname    string `gorm:"column:firstname"`
    Lastname  string `gorm:"column:lastname"`
}

func  main() {
  params := map[string]interface{} {
    "Firstname" : "MyFirstName",
    "Lastname" : "LastName" ,
 }
    db, _ := database.NewStorage("postgres", "testdb")


    err := db.DB.Debug().Model(&Usertable{}).Create(params)
    if err != nil {
        fmt.Println("Error :=", err)
    } else {
        fmt.Println("Success")
    }

}

Answer 1

You set a map[string]interface{} to insert, but gorm expects to pass a struct

user := models.Usertable{
    Firstname: "MyFirstName",
    Lastname:  "LastName",
}

result := db.DB.Debug().Create(&user)