为什么我的数据库列的值始终为0?

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英文:

Why is the value of my database column always 0?

问题

我正在使用go-gorm从PostgreSQL数据库中获取值。相关的代码如下所示:

type Chip struct {
    UUID    string `db:"uuid"`
    URL     string `db:"url"`
    N       int    `db:"n"`
    Pack_ID int    `db:"pack_id"`
}

func getChip(uuid string) (Chip, error) {
    var c Chip
    err := DB.Model(Chip{}).Where("uuid = ?", uuid).First(&c)
    return c, err.Error
}

当我将UUID字符串传递给getChip函数时,返回的行是正确的,所有的值都是正确的,除了c.Pack_ID始终为0。顺便说一下,从未出现过Pack_ID0的行。

这是来自pgAdminIII的屏幕截图,希望能解决问题:

为什么我的数据库列的值始终为0?

有什么想法可能出了什么问题吗?我完全不知所措...

英文:

I'm using go-gorm to fetch values from a PostgreSQL database. The relevant code is shown below:

type Chip struct {
	UUID    string `db:uuid`
	URL     string `db:url`
	N       int    `db:n`
	Pack_ID int    `db:pack_id`
}

func getChip(uuid string) (Chip, error) {
	var c Chip
	err := DB.Model(Chip{}).Where("uuid = ?", uuid).First(&c)
	return c, err.Error
}

When I pass a UUID string to getChip, the correct row is returned and all values are correct except for c.Pack_ID, which is always 0. Incidentally there is never a row for which Pack_ID is 0.

Here is a screenshot from pgAdminIII, which I hope will shed some light on the problem:

为什么我的数据库列的值始终为0?

Any ideas as to what might be going wrong? I'm at a complete loss, here...

答案1

得分: 5

你正在使用的结构标签似乎格式不正确。结构标签应该是以下形式:

name:"value"

但你的标签中缺少了值周围的引号:

name:value

请尝试进行修正。否则,Go中的结构标签解析器将无法工作,因为它依赖于这些引号,可以在结构标签解析器的实现中看到。

关于特定的结构标签:你确定应该使用db吗?根据Gorm文档,你可能想使用gorm:"column:..."。我原本期望你的类型定义是:

type Chip struct {
    UUID    string `gorm:"column:uuid;primary_key"`
    URL     string `gorm:"column:url"`
    N       int    `gorm:"column:n"`
    Pack_ID int    `gorm:"column:pack_id"`
}
英文:

The struct tags you're using appear to be malformed. A struct tag should be of the form:

name:"value"

but what you've got is missing the quotes around the value:

name:value

Try correcting this. Otherwise, the struct tag parser in Go has no chance to work, as it depends on those quotes, as seen in the struct tag parser implementation.

With regards to specific struct tags: are you sure you're supposed to use db? According to the Gorm documentation, you probably want to use gorm:"column:...". I was expecting your type definition to be:

type Chip struct {
    UUID    string `gorm:"column:uuid;primary_key"`
    URL     string `gorm:"column:url"`
    N       int    `gorm:"column:n"`
    Pack_ID int    `gorm:"column:pack_id"`
}

huangapple
  • 本文由 发表于 2015年3月30日 05:14:38
  • 转载请务必保留本文链接:https://go.coder-hub.com/29334915.html
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