duancuisan2503
2015-03-21 16:14
浏览 397

golang反射,获取指向结构字段值的指针

I'm trying to make a function that converts a struct in the way mysql rows.Scan function needs it, so I don't need to pass manually lots of parameters.

Note: I know the existence of sqlx and the alternative of writing manually in separate lines every pointer, but I'd like to solve it in this way as I'm learning go and want to understand what's going on.

The error I get with this solution is:
panic: sql: Scan error on column index 0: destination not a pointer to me looks like valueField.Addr().Pointer() should be a Pointer to the value. The following is a simplification of my code.

type User struct {
    Name string
    Age  int
}

func StrutForScan(u interface{}) []interface{} {
    val := reflect.ValueOf(u).Elem()
    v := make([]interface{}, val.NumField())
    for i := 0; i < val.NumField(); i++ {
        valueField := val.Field(i)
        v[i] = valueField.Addr().Pointer()
    }
    return v
}

func ListUsers {
    rows, err := db.Query("SELECT * FROM users")
    PanicIf(err)
    var user User
    for rows.Next() {
        err := rows.Scan(StrutForScan(&user)...)
        PanicIf(err)
        fmt.Printf("
Name: %s, Age: %s", user.Name, string(user.Age))

    }
}
  • 写回答
  • 好问题 提建议
  • 追加酬金
  • 关注问题
  • 邀请回答

1条回答 默认 最新

相关推荐 更多相似问题