MySQL 的位类型映射到哪个 Go 类型?

2022-01-01 00:00:00 orm mysql go beego

我之前用过Java，所以数据库表中有些列的类型是bit(1).但是现在我想用 beego 来重建我的项目，我不想改变我的数据库表(需要做很多).我在我的项目中使用 beego 的 orm.那么我应该使用哪种 Go 类型?

I used Java before, so some columns' type in database table is bit(1). But now I want to use beego to rebuild my project and I don't want to alter my database table (need do much). I use beego's orm in my project. So which Go type should I use?

这样的表和删除的列有问题:

Table like this and the deleted column has the question:

+--------------+--------------+------+-----+---------+-------+
| Field        | Type         | Null | Key | Default | Extra |
+--------------+--------------+------+-----+---------+-------+
| id           | varchar(255) | NO   | PRI | NULL    |       |
| created_time | datetime     | YES  |     | NULL    |       |
| deleted      | bit(1)       | NO   |     | NULL    |       |
| updated_time | datetime     | YES  |     | NULL    |       |
| icon_class   | varchar(255) | YES  |     | NULL    |       |
| mark         | varchar(255) | YES  |     | NULL    |       |
| name         | varchar(255) | YES  |     | NULL    |       |
| parent       | varchar(255) | YES  |     | NULL    |       |
+--------------+--------------+------+-----+---------+-------+

像这样去结构:

type BaseModel struct {
    Id          string           `orm:"pk";form:"id"`
    CreatedTime time.Time        `orm:"auto_now_add;type(datetime)";form:"-"`
    UpdatedTime time.Time        `orm:"auto_now;type(datetime)";form:"-"`
    Deleted     bool `form:"-"`
}

当我在我的代码中使用 bool 时，错误如下:

When I use bool in my code, the error like this:

`[0]` convert to `*orm.BooleanField` failed, field: shareall-go/models.Category.BaseModel.Deleted err: strconv.ParseBool: parsing "x00": invalid syntax

推荐答案

Sqlx 还为这种情况创建了一个自定义的 bool 数据类型并且它工作正常.相关代码链接

Sqlx has created also a custom bool datatype for such situations and it works fine. Link to related code

// BitBool is an implementation of a bool for the MySQL type BIT(1).
// This type allows you to avoid wasting an entire byte for MySQL's boolean type TINYINT.
type BitBool bool

// Value implements the driver.Valuer interface,
// and turns the BitBool into a bitfield (BIT(1)) for MySQL storage.
func (b BitBool) Value() (driver.Value, error) {
    if b {
        return []byte{1}, nil
    } else {
        return []byte{0}, nil
    }
}

// Scan implements the sql.Scanner interface,
// and turns the bitfield incoming from MySQL into a BitBool
func (b *BitBool) Scan(src interface{}) error {
    v, ok := src.([]byte)
    if !ok {
        return errors.New("bad []byte type assertion")
    }
    *b = v[0] == 1
    return nil
}

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