How to map a `[]int` type to a string type in SQL? about gorm HOT 1 CLOSED

// import "database/sql/driver"
var _ driver.Valuer = (RoleIds)(nil)  // you will get compile error at this line
// import "database/sql"
var _ sql.Scanner = (*RoleIds)(nil)

func (m RoleIds) Value() (driver.Value, error) {
    if  len(m) == 0 {
        return "", nil
    }
    strs := make([]string, len(m))
    for i, v := range m {
        strs[i] = strconv.FormatInt(v, 10)
    }
    return strings.Join(strs, ","), nil
}