How to print all the values of a variable outside a loop? - mysql

Question

In this code, I have a function in which I find the users' names. It finds them and prints all the names inside the loop but when I return the s variable outside the loop, it prints only the first name. It does not print all the names.
Although I append s variable in another variable also but still does not work.
type Signup struct {
Names string
Emails string
}
func FindNames() string {
db := Connect()
var s string
rows, err := db.Query("select names from Signup")
if err != nil {
log.Fatal(err)
}
defer rows.Close()
for rows.Next() {
var signup Signup
err := rows.Scan(&signup.Names)
if err != nil {
log.Fatal(err)
}
// s = signup.Names
// fmt.Println(s)
s = fmt.Sprintf("%s", signup.Names)
}
return s
}

Answer 1

When looping over stuff it'd make sense to put the results in a list, then do some actions on the results. Or to use a stringbuilder (as it's faster).
Example with list
type Signup struct {
Names string
Emails string
}
func FindNames() string {
db := Connect()
var s string
rows, err := db.Query("select names from Signup")
if err != nil {
log.Fatal(err)
}
defer rows.Close()
var names []string
for rows.Next() {
var signup Signup
err := rows.Scan(&signup.Names)
if err != nil {
log.Fatal(err)
}
names = append(names, signup.Names)
}
return strings.Join(names, "\n") // newline (\n) character to print multiple lines.
}
Stringbuilder
func FindNames() string {
db := Connect()
var s string
rows, err := db.Query("select names from Signup")
if err != nil {
log.Fatal(err)
}
defer rows.Close()
var sb strings.Builder
for rows.Next() {
var signup Signup
err := rows.Scan(&signup.Names)
if err != nil {
log.Fatal(err)
}
sb.WriteString(signup.Names)
sb.WriteRune('\n')
}
return sb.String()
}