Gen Delete

Delete record

When deleting a record, it needs to have any conditions or it will raise error ErrMissingWhereClause, for example:

e := query.Email

// Email's ID is `10`
e.WithContext(ctx).Where(e.ID.Eq(10)).Delete()
// DELETE from emails where id = 10;

// Delete with additional conditions
e.WithContext(ctx).Where(e.ID.Eq(10), e.Name.Eq("modi")).Delete()
// DELETE from emails where id = 10 AND name = "modi";

result, err := e.WithContext(ctx).Where(e.ID.Eq(10), e.Name.Eq("modi")).Delete()

result.RowsAffected // affect rows number
err                 // error

Delete with primary key

GEN allows to delete objects using primary key(s) with inline condition, it works with numbers.

u.WithContext(ctx).Where(u.ID.In(1,2,3)).Delete()
// DELETE FROM users WHERE id IN (1,2,3);

Batch Delete

The specified value has no primary value, GEN will perform a batch delete, it will delete all matched records

e := query.Email

e.WithContext(ctx).Where(e.Name.Like("%modi%")).Delete()
// DELETE from emails where email LIKE "%modi%";

Soft Delete

If your model includes a gorm.DeletedAt field (which is included in gorm.Model), it will get soft delete ability automatically!

When calling Delete, the record WON’T be removed from the database, but GORM will set the DeletedAt‘s value to the current time, and the data is not findable with normal Query methods anymore.

// Batch Delete
u.WithContext(ctx).Where(u.Age.Eq(20)).Delete()
// UPDATE users SET deleted_at="2013-10-29 10:23" WHERE age = 20;

// Soft deleted records will be ignored when querying
users, err := u.WithContext(ctx).Where(u.Age.Eq(20)).Find()
// SELECT * FROM users WHERE age = 20 AND deleted_at IS NULL;

If you don’t want to include gorm.Model, you can enable the soft delete feature like:

type User struct {
    ID      int
    Deleted gorm.DeletedAt
    Name    string
}

Find soft deleted records

You can find soft deleted records with Unscoped

users, err := db.WithContext(ctx).Unscoped().Where(u.Age.Eq(20)).Find()
// SELECT * FROM users WHERE age = 20;

Delete permanently

You can delete matched records permanently with Unscoped

o.WithContext(ctx).Unscoped().Where(o.ID.Eq(10)).Delete()
// DELETE FROM orders WHERE id=10;

Delete Associations

Remove the relationship between source & arguments if exists, only delete the reference, won’t delete those objects from DB.

u := query.User

u.Languages.Model(&user).Delete(&languageZH, &languageEN)

u.Languages.Model(&user).Delete([]*Language{&languageZH, &languageEN}...)

Delete with Select

You are allowed to delete selected has one/has many/many2many relations with Select when deleting records, for example:

u := query.User

// delete user's account when deleting user
u.Select(u.Account).Delete(&user)

// delete user's Orders, CreditCards relations when deleting user
db.Select(u.Orders.Field(), u.CreditCards.Field()).Delete(&user)

// delete user's has one/many/many2many relations when deleting user
db.Select(field.AssociationsFields).Delete(&user)