Soft Delete

https://gorm.io/docs/delete.html#Soft-Delete

import "gorm.io/plugin/soft_delete"

type User struct {
  ID        uint
  Name      string
  DeletedAt soft_delete.DeletedAt
}

// Query
SELECT * FROM users WHERE deleted_at = 0;

// Delete
UPDATE users SET deleted_at = /* current unix second */ WHERE ID = 1;

Specify Time Unit

We now support ms and ns timestamp when filling the deleted_at col, only need to specify tag gorm:"softDelete:milli" or gorm:"softDelete:nano".

type User struct {
  ID    uint
  Name  string
  DeletedAt soft_delete.DeletedAt `gorm:"softDelete:milli"`
  // DeletedAt soft_delete.DeletedAt `gorm:"softDelete:nano"`
}

// Query
SELECT * FROM users WHERE deleted_at = 0;

// Delete
UPDATE users SET deleted_at = /* current unix milli second or nano second */ WHERE ID = 1;

Flag Mode

flag mode will use 0, 1 to mark data as deleted or not, 1 means deleted

type User struct {
  ID    uint
  Name  string
  IsDel soft_delete.DeletedAt `gorm:"softDelete:flag"`
}

// Query
SELECT * FROM users WHERE is_del = 0;

// Delete
UPDATE users SET is_del = 1 WHERE ID = 1;

Mixed Mode

mixed mode will use 0, 1 to mark data as deleted or not, 1 means deleted, and store delete time

type User struct {
  ID        uint
  Name      string
  DeletedAt time.Time
  IsDel     soft_delete.DeletedAt `gorm:"softDelete:flag,DeletedAtField:DeletedAt"`
}

// Query
SELECT * FROM users WHERE is_del = 0;

// Delete
UPDATE users SET is_del = 1, deleted_at = /* current unix second */ WHERE ID = 1;

support mixed mode specify time unit, e.g. gorm:"softDelete:flag,DeletedAtField:DeletedAt" or gorm:"softDelete:flag,DeletedAtField:DeletedAt,DeletedAtFieldUnit:milli" or gorm:"softDelete:flag,DeletedAtField:DeletedAt,DeletedAtFieldUnit:nano".

type User struct {
  ID        uint
  Name      string
  DeletedAt int64
  IsDel     soft_delete.DeletedAt `gorm:"softDelete:flag,DeletedAtField:DeletedAt,DeletedAtFieldUnit:milli"`
}

// Query
SELECT * FROM users WHERE is_del = 0;

// Delete
UPDATE users SET is_del = 1, deleted_at = /* current unix milli second second*/ WHERE ID = 1;

Mixed Mode with Delete ID Field

Maintaining Unique Key Integrity

This allows you to record the original ID of a deleted record in another field. By doing so, you can maintain the integrity of unique keys by allowing new records with the same unique key to be inserted without conflict.

Example

Assume we have a User model where the Email field needs to be unique. By storing the original ID in the DeletedId field and creating a composite unique key with Email and DeletedId, you can insert a new record without violating the unique constraint even after soft deleting an existing record.

type User struct {
ID            uint
Name          string
Email         string
DeletedId     uint // Stores the original ID of the deleted record
IsDel         soft_delete.DeletedAt    `gorm:"softDelete:flag,DeletedIDField:DeletedId,DeletedIDFromField:ID"` // use `1` `0`
}

// Query
SELECT * FROM users WHERE is_del = 0;

// Delete
UPDATE users SET is_del = 1, deleted_id = /* value from ID */ WHERE ID = 1;