golang杜松子酒gorm插入并设置primary_key但primary_key却为空

Question

我使用gin gorm mysql构建应用程序。

我在model.go中将topic_id primary_key auto_increment设置为非null，如下所示：

type Topic struct {
    gorm.Model
    TopicId    uint64 `gorm:"PRIMARY_KEY;AUTO_INCREMENT;NOT NULL"`
    TopicName  string
    TopicDesc  string
    OwnerId    int
    CreateIP   string
    CreateTime uint64
    UpdateTime uint64
}

在service.go中创建主题

type TopicCreateService struct{
    TopicName string `form:"topic_name" json:"topic_name" binding:"required,min=1,max=30"`
    TopicDesc string `form:"topic_desc" json:"topic_desc" binding:"required,min=1,max=300"`
    OwnerId int `form:"owner_id" json:"owner_id" binding:"required,min=1,max=30"`
}

func (service *TopicCreateService) Create(c *gin.Context) serializer.Response{
    topic := model.Topic{
        TopicName:service.TopicName,
        TopicDesc:service.TopicDesc,
        OwnerId:service.OwnerId,
        CreateIP:c.ClientIP(),
        CreateTime:uint64(time.Now().UnixNano()),
        UpdateTime:0,
    }

    if err:=model.DB.Create(&topic).Error;err!=nil{
        return serializer.ParamErr("创建话题失败", err)
    }
    return serializer.BuildTopicResponse(topic)
}

我希望topic_id是我的primary_key，而不是null自动递增。怎么了

Answer 1

您已在结构中包含gorm.Model。这意味着您的模型迁移/数据库将给出错误：

Error 1075: Incorrect table definition; there can be only one auto column and it must be defined as a key

如果从gorm.Model结构中删除Topic，那会很好。

package model

import (
    `github.com/jinzhu/gorm`
)

type WithoutModel struct {
    MyId int64 `gorm:"primary_key;auto_increment;not_null"`
    Name string
}

func ModelSave(tx *gorm.DB) {
    wo := WithoutModel{Name:"Without the model"}
    tx.Save(&wo)
}

运行ModelSave几次后，我有：

MariaDB [gmodel]> select * from without_models;
+-------+-------------------+
| my_id | name              |
+-------+-------------------+
|     1 | Without the model |
|     2 | Without the model |
+-------+-------------------+
2 rows in set (0.000 sec)