Linq Lambda 表达式 Where 条件和性能问题

Question

我使用 linq lambda 表达式创建了 where 条件以进行报告。我的条件运行非常缓慢或抛出错误。

错误详情：演进超时。

我怎样才能找到正确的查询？

我的代码：

var query = Worker.Members
        .Where(u => string.IsNullOrEmpty(model.TcNumber) || u.TcNumber.Contains(model.TcNumber))
        .Where(u => string.IsNullOrEmpty(model.FullName) || u.FullName.Contains(model.FullName))
        .Where(u => model.BirthYear == null || u.BirthDate.Year >= model.BirthYear)
        .Where(u => model.BirthYearLevel == null || u.BirthDate.Year <= model.BirthYearLevel)
        .Where(u => model.BirthYearLevel == null || u.BirthDate.Year <= model.BirthYearLevel)
        .Where(u => model.GenderId == null || u.GenderId == model.GenderId)
        .Where(u => model.DistrictCode == null || u.Contacts.Any(c => c.DistrictCode == model.DistrictCode && c.IsActive))
        .Where(u => model.StreetCode == null || u.Contacts.Any(c => c.StreetCode == model.StreetCode && c.IsActive))
        .Where(u => model.ExteriorDoor == null || u.Contacts.Any(c => c.ExteriorDoor == model.ExteriorDoor && c.IsActive))
        .Where(u => model.InteriorDoor == null || u.Contacts.Any(c => c.InteriorDoor == model.InteriorDoor && c.IsActive))
        .Where(u => model.DisabledGroupId == null || u.Disableds.Any(d => d.ReportDisabledGroups.Any(c => c.DisabledGroupId == model.DisabledGroupId)))
        .Where(u => model.ContributionTypeId == null || u.Demands.Any(d => d.ContributionTypeId == model.ContributionTypeId && !d.IsDeleted))
        .Where(u => model.DemandStatusId == null || u.Demands.Any(d => d.DemandStatusId == model.DemandStatusId && !d.IsDeleted))
        .Where(u => model.DemandDateStart == null || u.Demands.Any(d => d.DemandDate >= model.DemandDateStart && !d.IsDeleted))
        .Where(u => model.DemandDateEnd == null || u.Demands.Any(d => d.DemandDate <= model.DemandDateEnd && !d.IsDeleted))
        .Where(u => u.IsTcCitizen == model.IsForeign)
        .Where(u => u.IsDisabled == model.IsDisabled)
        .Where(u => u.IsAlive == model.IsAlive);

Answer 1

这里正确的模式（假设Worker.Members是一个IQueryable，而不是一个IEnumerable）是有条件地添加条件，像这样：

var query = Worker.Members;

if (!string.IsNullOrEmpty(model.TcNumber))
    query = query.Where(u => u.TcNumber.Contains(model.TcNumber));
if (!string.IsNullOrEmpty(model.FullName)
    query = query.Where(u => u.FullName.Contains(model.FullName));
if (!model.BirthYear == null)
    query = query.Where(u => u.BirthDate.Year >= model.BirthYear);
. . .

Answer 2

你检查了吗？ Here detailed descriptions are given.