我有这个Go代码:
package main
import (
"fmt"
"database/sql"
_"github.com/go-sql-driver/mysql"
"time"
)
type User struct {
id uint32
name string
email string
rating uint8
subscription uint8
date_registered time.Time
online string
}
// main entry point
func main() {
// setup db connection
db, err := sql.Open("mysql", "user:@tcp(127.0.0.1:3306)/c9?parseTime=true")
if err != nil {
fmt.Println(err)
}
defer db.Close()
// query
rows, err := db.Query("SELECT * FROM users WHERE id = ?", 1)
if err != nil {
fmt.Println(err)
}
defer rows.Close()
usr := User{}
for rows.Next() {
err := rows.Scan(&usr.id, &usr.name, &usr.email, &usr.rating, &usr.subscription, &usr.date_registered, &usr.online)
if err != nil {
fmt.Println(err)
}
}
fmt.Println(usr)
err = rows.Err()
if err != nil {
fmt.Println(err)
}
}
这是我从MySQL控制台获得的:
mysql> describe users;
+-----------------+---------------------+------+-----+-------------------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-----------------+---------------------+------+-----+-------------------+----------------+
| id | int(10) unsigned | NO | PRI | NULL | auto_increment |
| name | varchar(50) | NO | | NULL | |
| email | varchar(50) | NO | | NULL | |
| rating | tinyint(3) unsigned | YES | | NULL | |
| subscription | tinyint(3) unsigned | NO | | 0 | |
| date_registered | timestamp | NO | | CURRENT_TIMESTAMP | |
| online | char(1) | NO | | N | |
+-----------------+---------------------+------+-----+-------------------+----------------+
7 rows in set (0.00 sec)
mysql> SELECT * FROM users;
+----+------------+-----------------------+--------+--------------+---------------------+--------+
| id | name | email | rating | subscription | date_registered | online |
+----+------------+-----------------------+--------+--------------+---------------------+--------+
| 1 | alakhazamm | abcdefghhhh@gmail.com | NULL | 0 | 2014-10-28 15:37:44 | N |
+----+------------+-----------------------+--------+--------------+---------------------+--------+
1 row in set (0.00 sec)
在 .Scan()
之后, fmt.Println(usr)
打印
{1 alakhazamm abcdefghhhh@gmail.com 0 0 {0 0 <nil>} }
结构的最后两个字段是错误的,但我不知道为什么 . 我尝试在结构定义中使用 date_registered string
,但是在 .Scan()
之后我得到一个空字符串 . 我've also read in the driver'的文档 ?parseTime=true
将MySQL DATE和DATETIME值解析为time.Time,但是他们当前没有使用.1837341_m .
我错过了一些重要的内容,还是图书馆的错误/缺失功能?
2 回答
我知道这是一个老问题但是我在Open公告中缺少这个参数:
See here
我找到了错误的原因 .
由于
rating
在数据库中为NULL,因此扫描程序发出错误我已经更新了数据库行,现在
usr.date_registered
和usr.online
保持正确的值 .我想我必须使MySQL字段为NOT NULL并且只使用-1来表示未初始化的值 .