C# 在linq查询中处理空数组

我有一个linq查询，其中包含一个值数组。我遇到的问题是，如果数组为空/null，它将中断我的查询。如何在linq查询中处理这个问题。我的另一个选择是在执行linq查询之前检查数组的长度，但我想知道是否可以在查询中包含此检查

代码

试试这个：

var entities = await _DbContext.MasterProductView
                                .Where(e => query.SubCategory.Any() ? e.BusinessUnit == query.BusinessUnit &&
                                            e.Category == query.Category &&
                                            query.SubCategory.Contains(e.SubCategory) : e.BusinessUnit == query.BusinessUnit &&
                                            e.Category == query.Category)
                                .Select(e => new OptionDto() { Value = e.Brand, Label = e.Brand })
                                .Distinct()
                                .OrderBy(e => e.Label)
                                .ToListAsync(cancellationToken);

---

空数组可能没有问题，只有空数组。您可以将与结合使用

var entities = await _DbContext.MasterProductView
                                .Where(e => query.SubCategory.Any() ? e.BusinessUnit == query.BusinessUnit &&
                                            e.Category == query.Category &&
                                            query.SubCategory.Contains(e.SubCategory) : e.BusinessUnit == query.BusinessUnit &&
                                            e.Category == query.Category)
                                .Select(e => new OptionDto() { Value = e.Brand, Label = e.Brand })
                                .Distinct()
                                .OrderBy(e => e.Label)
                                .ToListAsync(cancellationToken);

// Properties
public string BusinessUnit { get; set; }
public string Category { get; set; }
public string[] SubCategory { get; set; }

var entities = await _DbContext.MasterProductView
    .Where(e => e.BusinessUnit == query.BusinessUnit &&
                e.Category == query.Category &&
                query.SubCategory?.Contains(e.SubCategory) ?? false)
    .Select(e => new OptionDto() { Value = e.Brand, Label = e.Brand })
    .Distinct()
    .OrderBy(e => e.Label)
    .ToListAsync(cancellationToken);