在 foreach 中使用 EF Core 包含方法可能是一个性能问题

Question

These days I am working on a project, and this project depends on another project that will play the repository, my repository project based on Generic Repository pattern . In my repository project I created a method that will get all data from a received entity and load data from selected entities in a received expression.

My method:

public List<TEntity> GetAll<TEntity>(params Expression<Func<TEntity, object>>[] expressions) where TEntity : class
{
    var result = new List<TEntity>();

    foreach (var expression in expressions)
    {
        result = Context.Set<TEntity>().Include(expression).ToList();
    }

    return result;
}

The question:

As you will notice in the above method I used Include method inside an iteration ( Foreach ), so my question is: is that using of Include inside foreach have a performance issue or any other problem?

Answer 1

Probably you need this:

public List<TEntity> GetAll<TEntity>(params Expression<Func<TEntity, object>>[] expressions) where TEntity : class
{
    var query = Context.Set<TEntity>().AsQueryable();

    foreach (var expression in expressions)
    {
        query = query.Include(expression);
    }

    return query.ToList();
}