Method StructScan

sqlx.go:602–637

StructScan is like sql.Rows.Scan, but scans a single Row into a single Struct. Use this and iterate over Rows manually when the memory load of Select() might be prohibitive. *Rows.StructScan caches the reflect work of matching up column positions to fields to avoid that overhead per scan, which mea

(dest interface{})

// positions to fields to avoid that overhead per scan, which means it is not safe
// to run StructScan on the same Rows instance with different struct types.
func (r *Rows) StructScan(dest interface{}) error {
	v := reflect.ValueOf(dest)

	if v.Kind() != reflect.Ptr {
		return errors.New("must pass a pointer, not a value, to StructScan destination")
	}

	v = v.Elem()

	if !r.started {
		columns, err := r.Columns()
		if err != nil {
			return err
		}
		m := r.Mapper

		r.fields = m.TraversalsByName(v.Type(), columns)
		// if we are not unsafe and are missing fields, return an error
		if f, err := missingFields(r.fields); err != nil && !r.unsafe {
			return fmt.Errorf("missing destination name %s in %T", columns[f], dest)
		}
		r.values = make([]interface{}, len(columns))
		r.started = true
	}

	err := fieldsByTraversal(v, r.fields, r.values, true)
	if err != nil {
		return err
	}
	// scan into the struct field pointers and append to our results
	err = r.Scan(r.values...)
	if err != nil {
		return err
	}
	return r.Err()
}

// Connect to a database and verify with a ping.
func Connect(driverName, dataSourceName string) (*DB, error) {