Interview Question

How can you delete an existing entity in Entity Framework Core?

Answer

EF Core provides multiple ways to delete entities. Here are the main approaches:

1. Find and Delete

using (var context = new ApplicationDbContext())
{
    var customer = await context.Customers.FindAsync(1);
    context.Customers.Remove(customer);
    await context.SaveChangesAsync();
}

2. Delete Without Loading

using (var context = new ApplicationDbContext())
{
    var customer = new Customer { Id = 1 };
    context.Customers.Remove(customer);
    // or context.Entry(customer).State = EntityState.Deleted;
    await context.SaveChangesAsync();
}

3. Bulk Delete

using (var context = new ApplicationDbContext())
{
    // Delete multiple entities
    await context.Customers
        .Where(c => c.LastLoginDate < DateTime.Now.AddYears(-1))
        .ExecuteDeleteAsync(); // Requires EF Core 7.0+
}

Key Points 💡

• First approach is safer as it verifies entity exists
• Second approach is more efficient for known entities
• Use bulk delete for removing multiple entities
• Consider soft delete pattern for audit trails

Common Follow-up Questions

1. What is soft delete and when should you use it?
2. How do you handle cascade deletes?
3. How can you implement delete with concurrency checks?