mysql - 如何使用 gorm 获取多个用户的数据？

Question

数据库:MySql我有两个结构如下:

type Person struct {
    gorm.Model
    Name    string
    Address string
}

type Address struct {
    gorm.Model
    PersonID int
    Address  []Address
}

我想获取多个有地址的人的数据。我这样试过:

var result []Person
db.Table("persons").Select("persons.id,persons.created_at, persons.updated_at,persons.deleted_at,persons.name,addresses.address").Joins("inner join addresses on addresses.person_id = persons.id").Scan(&result)

我得到了结果:

[
  {
    ID: 13,
    CreatedAt: '2018-03-28T16:25:43+05:30',
    UpdatedAt: '2018-03-28T16:28:31+05:30',
    DeletedAt: null,
    Name: 'roshan',
    Address: null
  },
  {
    ID: 13,
    CreatedAt: '2018-03-28T16:25:43+05:30',
    UpdatedAt: '2018-03-28T16:28:31+05:30',
    DeletedAt: null,
    Name: 'roshan',
    Address: null
  },
  {
    ID: 14,
    CreatedAt: '2018-03-28T16:25:43+05:30',
    UpdatedAt: '0001-01-01T00:00:00Z',
    DeletedAt: null,
    Name: 'kunal2',
    Address: null
  }
];

导出结果为

[
  {
    ID: 13,
    CreatedAt: '2018-03-28T16:25:43+05:30',
    UpdatedAt: '2018-03-28T16:28:31+05:30',
    DeletedAt: null,
    Name: 'roshan',
    Address: ['pune', 'nagpur']
  },
  {
    ID: 14,
    CreatedAt: '2018-03-28T16:25:43+05:30',
    UpdatedAt: '0001-01-01T00:00:00Z',
    DeletedAt: null,
    Name: 'kunal2',
    Address: ['New York']
  }
];

Answer 1

首先，您可能应该将模型声明更改为此

type Person struct {
    gorm.Model
    Name    string
    Address []Address
}

type Address struct {
    gorm.Model
    PersonID int
}

然后要预加载关联，您可以使用此查询

var person []Person

err := db.Preload("Address").Find(&person).Error

你的个人参数将是来自具有预加载地址的数据库的结果