Creating an array/slice to store DB Query results in Golang

Go has a built-in append function for exactly this purpose. It takes a slice and one or more elements and appends those elements to the slice, returning the new slice. Additionally, the zero value of a slice (nil) is a slice of length zero, so if you append to a nil slice, it will work. Thus, you can do:

type User struct {
    Id    int
    Title string
}

func Find_users(db *sql.DB) {
    // Query the DB
    rows, err := db.Query(`SELECT u.id, u.title FROM users u;`)
    if err != nil {
        log.Fatal(err)
    }
    defer rows.Close()

    var users []User
    for rows.Next() {
        err := rows.Scan(&id, &title)
        if err != nil {
            log.Fatal(err)
        }

        log.Println(id, title)
        users = append(users, User{Id: id, Title: title})
    }
    if err := rows.Err(); err != nil {
        log.Fatal(err)
    }

    // ...
}

User appending to a slice:

type DeviceInfo struct {
     DeviceName     string
     DeviceID       string
     DeviceUsername string
     Token          string
}

func QueryMultiple(db *sql.DB){
    var device DeviceInfo
    sqlStatement := `SELECT "deviceName", "deviceID", "deviceUsername", 
                 token FROM devices LIMIT 10`
    rows, err := db.Query(sqlStatement)
    if err != nil {
       panic(err)
    }
    defer rows.Close()
    var deviceSlice []DeviceInfo
    for rows.Next(){
        rows.Scan(&device.DeviceID, &device.DeviceUsername, &device.Token, 
                  &device.DeviceName)
         deviceSlice = append(deviceSlice, device)
    }
    fmt.Println(deviceSlice)
}