In the Go SQL docs they give an example here of a query that only returns 1 column (poor example in my opinion, at least return 2...)
age := 27
rows, err := db.Query("SELECT name FROM users WHERE age=?", age)
if err != nil {
log.Fatal(err)
}
for rows.Next() {
var name string
if err := rows.Scan(&name); err != nil {
log.Fatal(err)
}
fmt.Printf("%s is %d
", name, age)
}
if err := rows.Err(); err != nil {
log.Fatal(err)
}
The docs state here that Scan copies the columns in the current row into the values pointed at by dest.
How does this work with a struct, lets say I have a struct
type User struct{
Name string
Age int
}
and I modify my query to SELECT name, age from users where age=?
How do I unpack *Rows into my struct? I did find this example, but it didn't deal with structs. I will be following Active Record pattern conventions so my structs will map to my database via snake case conversion.
Looking at the source, it seems the copy is done with ... syntax on destination pointers:
func (rs *Rows) Scan(dest ...interface{}) error
So in your example, you can do for instance:
for rows.Next() {
u := User{} // An empty user
...
if err := rows.Scan(&u.Name, &u.Age); err != nil {
...
}
}
As long as you pass the exact number of pointers, this should work, whether they are from a struct or not.