Postgresql Has-Many关系插入相同的id错误

Question

我有 2 个结构像这样的多对多关系：

type Domain struct {
    ID     uint    `gorm:"primaryKey;type:serial"`
    Emails []Email `gorm:"foreignKey:ID" "column:emails"`
}

type Email struct {
    ID      uint   `gorm:"primaryKey;type:serial"`
    Address string `gorm:"column:address"`
}

我在这里关注 gorm 的文档：https://gorm.io/docs/associations.html#Association-Mode

据我了解，当我们插入一条 Domain 记录时，gorm 首先将数组电子邮件 ([]Email) 插入数据库，我在尝试插入数据库时遇到了这样的问题：

var domain models.Domain
var emails []models.Email
for key, _ := range Output {
  emails = append(emails, models.Email{Address: key})
}
domain = models.Domain{
  Emails: emails,
}
dataAccess.Domain.Insert(domain) // db.Create(&domain)

这是我控制台的输出：

2020/09/10 10:37:46 /Users/tho/go/src/txxxx/exxxx/dataAccess/domains.go:18 ERROR: ON CONFLICT DO UPDATE command cannot affect row a second time (SQLSTATE 21000)
[362.162ms] [rows:0] INSERT INTO "emails" ("address","id") VALUES ('info@example.com',2),('d.apple@example.com',2) ON CONFLICT ("id") DO UPDATE SET "id"="excluded"."id" RETURNING "id"

2020/09/10 10:37:46 /Users/tho/go/src/txxxx/exxxx/dataAccess/domains.go:18 ERROR: ON CONFLICT DO UPDATE command cannot affect row a second time (SQLSTATE 21000)
[1078.499ms] [rows:1] INSERT INTO "domains" DEFAULT VALUES RETURNING "id"
ERRO[0050] Err: ERROR: ON CONFLICT DO UPDATE command cannot affect row a second time (SQLSTATE 21000)

Gorm 插入 2 封具有相同 ID 的电子邮件，因此 postresql 错误显示如上。我怎样才能避免相同的 id，因为它是 primaryKey 并且已经是 serial（autoIncrement）。

Answer 1

你需要改变

Emails []Email `gorm:"foreignKey:ID" "column:emails"`

至

Emails []Email `gorm:"foreignKey:DomainId" "column:domain_id"`

并添加

DomainId uint   `gorm:"column:domain_id"`

在type Email struct

尝试：

type Domain struct {
    ID     uint    `gorm:"primaryKey;type:serial"`
    Domain string  `gorm:"column:domain"`
    Emails []Email `gorm:"foreignKey:DomainId" "column:domain_id"`
}

type Email struct {
    ID       uint   `gorm:"primaryKey;type:serial"`
    Address  string `gorm:"column:address"`
    DomainId uint   `gorm:"column:domain_id"`
}

Postgresql Has-Many关系插入相同的id错误

Postgresql Has-Many relationship insert same id error

postgresql

go

go-gorm