GetAll(Expression<Func<T, bool>> filter = null, Func<IQueryable<T>, IOrderedQueryable<T>> orderBy = null, params Expression<Func<T, object>>[] includeProperties)
/// <summary>
/// Gets the first or default entity based on a predicate, orderby delegate and include delegate. This method default no-tracking query.
/// </summary>
/// <param name="selector">The selector for projection.</param>
/// <param name="predicate">A function to test each element for a condition.</param>
/// <param name="orderBy">A function to order elements.</param>
/// <param name="include">A function to include navigation properties</param>
/// <param name="disableTracking"><c>True</c> to disable changing tracking; otherwise, <c>false</c>. Default to <c>true</c>.</param>
/// <returns>An <see cref="IPagedList{TEntity}"/> that contains elements that satisfy the condition specified by <paramref name="predicate"/>.</returns>
/// <remarks>This method default no-tracking query.</remarks>
public TResult GetFirstOrDefault<TResult>(Expression<Func<TEntity, TResult>> selector,
Expression<Func<TEntity, bool>> predicate = null,
Func<IQueryable<TEntity>, IOrderedQueryable<TEntity>> orderBy = null,
Func<IQueryable<TEntity>, IIncludableQueryable<TEntity, object>> include = null,
bool disableTracking = true)
{
IQueryable<TEntity> query = _dbSet;
if (disableTracking)
{
query = query.AsNoTracking();
}
if (include != null)
{
query = include(query);
}
if (predicate != null)
{
query = query.Where(predicate);
}
if (orderBy != null)
{
return orderBy(query).Select(selector).FirstOrDefault();
}
else
{
return query.Select(selector).FirstOrDefault();
}
}