How to avoid duplicate row while gorm AutoMigrate - postgresql

Question

I want to insert to database from CSV file using gorm AutoMigrate and while inserting I want to avoid duplicate entry. How Can I achieve this? Please check the attached code.
type User struct {
gorm.Model
ID int64 `csv:"_" db:"id"`
FirstName string `csv:"First name" db:"first_name"`
LastName string `csv:"Last name" db:"last_name"`
Emails string `csv:"Emails" db:"emails"`
}
func main() {
file, err := os.Open(os.Args[1])
defer file.Close()
users := []User{}
err = gocsv.Unmarshal(file, &users)
db, err := gorm.Open(postgres.Open("host=xxx.xx.x.x user=database password=password dbname=database port=5432 sslmode=disable"))
err = db.AutoMigrate(&User{})
if err != nil {
panic(err)
}
result := db.Create(users)
if result.Error != nil {
panic(result.Error)
}
}
Example: Consider the below data
FIrst name
Last name
Emails
First
Name
first#example.com
Second
Name
second#example.com
Third
Name
Forth
Name
first#example.com
If we pass the above data, the first 3 rows should insert into the database i.e. we have to avoid duplicate email entries to the database. Thanks.
Note: If the email is empty then the row should be inserted into the database.

Answer 1

You have to sanitize "users" after err = gocsv.Unmarshal(file, &users)
Somethink like
func sanytize(arr []User) []User {
users := []User{}
mail := []string{}
for _, a := range arr {
if !contains(mail, a.Emails){
users = append(users, a)
}
mail = append(mail, a.Emails)
}
return users
}
func contains(arr []string, str string) bool {
for _, a := range arr {
if a == str {
return true
}
}
return false
}
....
err = gocsv.Unmarshal(file, &users)
users = sanytize(users)