How to Use destroy_all in Rails: Syntax and Examples

In Rails, use destroy_all to delete all records matching a condition while running callbacks and validations. It differs from delete_all by invoking model callbacks and ensuring dependent associations are handled.

Syntax

The destroy_all method is called on an ActiveRecord relation or model to delete all matching records. It runs callbacks like before_destroy and after_destroy for each record.

• Model.destroy_all: Deletes all records in the model's table.
• Model.where(condition).destroy_all: Deletes records matching the condition.

ruby

Model.destroy_all
Model.where(condition).destroy_all

Example

This example shows how to delete all users who are inactive using destroy_all. It runs callbacks for each user deleted.

ruby

class User < ApplicationRecord
  before_destroy :log_destroy

  private

  def log_destroy
    puts "Destroying user: #{id}"
  end
end

# Delete all inactive users
User.where(active: false).destroy_all

Output

Destroying user: 3
Destroying user: 7
Destroying user: 12

Common Pitfalls

One common mistake is confusing destroy_all with delete_all. destroy_all runs callbacks and validations, which can slow down deletion if many records exist. delete_all deletes directly in the database without callbacks.

Another pitfall is calling destroy_all on large datasets without batching, which can cause performance issues.

ruby

## Wrong: Using delete_all when callbacks are needed
User.where(active: false).delete_all

## Right: Use destroy_all to run callbacks
User.where(active: false).destroy_all

Quick Reference

Method	Description	Callbacks Run	Performance
destroy_all	Deletes records with callbacks and validations	Yes	Slower for many records
delete_all	Deletes records directly in DB without callbacks	No	Faster but skips callbacks

Key Takeaways

Use destroy_all to delete records while running callbacks and validations.

destroy_all can be slower than delete_all because it processes each record.

Avoid using destroy_all on very large datasets without batching.

Use where conditions with destroy_all to target specific records.

Remember delete_all skips callbacks and should be used only when callbacks are not needed.