Gorm - CreatedBy and UpdatedBy logic within models

[boreal shadow]

hello guys, it's been 1 day since i tried to achive this logic, i am not really sure if this applicable in gorm. i was from javascript background. kindly seeking for help

above is my company, which i would expect i could return user details whose created / updated this company object

type User struct {
    ID       uuid.UUID `gorm:"index:id,unique;type:uuid;default:gen_random_uuid();" json:"id"`
    Name     string    `json:"name" gorm:"not null" binding:"required"`
    Address  string    `json:"address,omitempty"`
    Username string    `json:"username" binding:"required" gorm:"not null"`
    Email    string    `gorm:"email:id,unique" json:"email" binding:"required" gorm:"not null"`
    Password string    `json:"password" binding:"required" gorm:"not null"`
    Role     string    `json:"role,omitempty" binding:"required" gorm:"not null"`

    CreatedBy           uuid.UUID `json:"createdBy" gorm:"type:uuid;default:NULL"`
    UpdatedBy           uuid.UUID `json:"updatedBy" gorm:"type:uuid;default:NULL"`
    CreatedBySuperAdmin []*User   `gorm:"constraint:OnUpdate:CASCADE,OnDelete:CASCADE;foreignKey:CreatedBy;references:ID" json:"createdBySuperAdmin"`
    UpdatedBySuperAdmin []*User   `gorm:"constraint:OnUpdate:CASCADE,OnDelete:CASCADE;foreignKey:UpdatedBy;references:ID" json:"updatedBySuperAdmin"`

    CompanyCreatedByUser []Company `gorm:"constraint:OnUpdate:CASCADE,OnDelete:CASCADE;foreignKey:CreatedBy;references:ID" json:"companyCreatedByUser"`
    CompanyUpdatedByUser []Company `gorm:"constraint:OnUpdate:CASCADE,OnDelete:CASCADE;foreignKey:UpdatedBy;references:ID" json:"companyUpdatedByUser"`

    //ClientCreatedByUser *Client `gorm:"constraint:OnUpdate:CASCADE,OnDelete:CASCADE;foreignKey:CreatedBy;references:ID" json:"clientCreatedByUser"`
    //ClientUpdatedByUser *Client `gorm:"constraint:OnUpdate:CASCADE,OnDelete:CASCADE;foreignKey:UpdatedBy;references:ID" json:"clientUpdatedByUser"`
    types.DefaultModelProperty
}

and here is my user model, which i would expect when i fetch this user i can see the companies that i created within this user

or here's the screenshot for the user model

the relation of company inside user model

here i tried to fetch the single user within a company object

but it gives me nil on the return for the User relation in company model

but within the database editor, they're both interconnected between each other

but gorm doesnt seem to understand this logic, or i might be wrong

[boreal shadow]

i've also readed the gorm's documentation about one-to-many or has many in this case

https://gorm.io/docs/has_many.html

but in their documentation, how does i retrieve the user whose created the credit card ? doesn't really explaining how

[fathom sage]

thats because gorm is a wrapper for SQL relational databases

what you are doing here is a pretty common whoopsie oopsie for beginners

you either use embedded structs or (better) use a proper relation that faces your needs

[fathom sage]

okay so ive replied too fast uve already found that documentation, see; gorm retrieves the Users, then it looks for foreign key constrains (for example the UserID uint in the CreditCard), it automatically detects those models

lemme show you an example;

type User struct {
    Id         uuid.UUID `json:"id" gorm:"type:char(36);primary_key"`
    CartID uuid.UUID `json:"cart_id" gorm:"foreignkey:UserID"`
    Cart   Cart      `json:"cart" gorm:"association_foreignkey:ID;foreignkey:CartID"`
}```
**CartID**: This field serves as the foreign key in the User model, linking it to the Cart model, it indicates which Cart is associated with a particular user

**Cart**: This field is a direct association to the Cart model, it is used to load the associated Cart when querying for a user. It's essentially a convenience field that allows you to access the associated Cart directly from a User instance

however if you only need the CartID for foreign key relationships and don't often need to access the full Cart data when working with a User, you should consider omitting the Cart field and fetching the Cart separately when needed, especially if working with sensitive data models or passwords as they can be easily ( & mistakenly ) shown where they shouldnt

[fathom sage]

the Cart model is also pretty simple:

type Cart struct {
    Id     uuid.UUID `json:"id" gorm:"type:char(36);primary_key"`
    UserId uuid.UUID `json:"user_id" gorm:"type:char(36);column:user_id"`
}```

The UserId here has the same usage as the CartId as described above