Question

早上好。我正在尝试减少LINQ查询的时间。在执行代码块期间，对于大型数据集，大约需要30-40秒才能完成，这太长了。

foreach (var patientVisitId in patientVisitIds)
            {
                var firstVisit = visitsWithBills.First(vb => vb.Visit.PatientVisitId == patientVisitId).Visit;
                firstVisit.Bills = (from visitBill in visitsWithBills
                                    where visitBill.Visit.PatientVisitId == patientVisitId
                                    select visitBill.Bill).ToList();


                visitTOs.Add(firstVisit);
            }

我尝试用.contains将where语句中的==替换为我所读的更快，这几乎使执行时间加倍。

    foreach (var patientVisitId in patientVisitIds)
    {
        var firstVisit = visitsWithBills.First(vb => vb.Visit.PatientVisitId == patientVisitId).Visit;
        firstVisit.Bills = (from visitBill in visitsWithBills
                            where visitBill.Visit.PatientVisitId.Contains(patientVisitId)
                            select visitBill.Bill).ToList();

        visitTOs.Add(firstVisit);
    }

这是firstVisit表示的对象。

public class VisitTO
    {
        #region { Instance properties }
    /// <summary>
    /// Gets or sets the bed/room number for the visit
    /// </summary>
    public string Bed { get; set; }

    /// <summary>
    /// Gets or sets the bills for the visit
    /// </summary>
    public List<BillTO> Bills { get; set; }

    /// <summary>
    /// Gets or sets the date of admission for the visit
    /// </summary>
    public DateTime DateOfAdmission { get; set; }

    /// <summary>
    /// Gets or sets the primary diagnosis for the patient
    /// </summary>
    public string DX1 { get; set; }

    /// <summary>
    /// Gets or sets the secondary diagnosis for the patient
    /// </summary>
    public string DX2 { get; set; }

    /// <summary>
    /// Gets or sets the tertiary diagnosis for the patient
    /// </summary>
    public string DX3 { get; set; }

    /// <summary>
    /// Gets or sets the quaternary diagnosis for the patient
    /// </summary>
    public string DX4 { get; set; }

    /// <summary>
    /// Gets or sets the quinary diagnosis for the patient
    /// </summary>
    public string DX5 { get; set; }

    /// <summary>
    /// Gets or sets the senary diagnosis for the patient
    /// </summary>
    public string DX6 { get; set; }

    /// <summary>
    /// Gets or sets whether the patient has been discharged
    /// </summary>
    public bool IsDischarged { get; set; }

    /// <summary>
    /// Gets or sets the patient's full name
    /// </summary>
    public string PatientName { get; set; }

    /// <summary>
    /// Gets or sets the patient's current visit ID
    /// </summary>
    public string PatientVisitId { get; set; }

    /// <summary>
    /// Gets or sets the patient's current visit ID
    /// </summary>
    public string PatientId { get; set; }

    /// <summary>
    /// Gets or sets the name of the patient's primary care physician
    /// </summary>
    public string PrimaryCarePhysician { get; set; }

    /// <summary>
    /// Gets or sets the hosting site
    /// </summary>
    public string Site { get; set; }

    /// <summary>
    /// Gets or sets the team assignment
    /// </summary>
    public string Team { get; set; }

    #endregion { Instance properties }
}

这里是BillTO对象。

public class BillTO
    {
        #region { Public instance properties }

        /// <summary>
        ///     Gets or sets the bill's date
        /// </summary>
        public DateTime Date { get; set; }

        /// <summary>
        ///     Gets or sets the name for the doctor on the bill
        /// </summary>
        public string DoctorName { get; set; }

        /// <summary>
        ///     Gets or sets the bill's type
        /// </summary>
        public string Type { get; set; }

        /// <summary>
        ///     Gets or sets the encounter for this bill
        /// </summary>
        public string Encounter { get; set; }

        /// <summary>
        ///     Gets or sets the CPT Code
        /// </summary>
        public string CptCode { get; set; }       

        #endregion { Public instance properties }
    }

数据库查询到获取列表。

private static readonly Func<MDataContext, IQueryable<VisitBillTO>> ActiveVisitsWithBillsQuery =
         CompiledQuery.Compile<MContext, IQueryable<VisitBillTO>>(
             dbContext => (
                       from visit in dbContext.AV
                       join bill in dbContext.ABills on visit.PatientVisitId equals bill.PatientVisitId
                      where (visit.BFlag == null || visit.BFlag != "BI")
                    orderby visit.PatientVisitId
                     select new VisitBillTO
                    {
                        Bill = new BillTO
                        {
                            Date = bill.Date.GetValueOrDefault(DateTime.Today),
                            DoctorName = bill.DoctorName,
                            Type = bill.Type,
                            Encounter = bill.Encounter,
                            CptCode = bill.CptCode
                        },
                        Visit = new VisitTO
                        {
                            Bed = visit.Bed,
                            DateOfAdmission = visit.DateOfAdmission.GetValueOrDefault(DateTime.Today),
                            DX1 = visit.DX1,
                            DX2 = visit.DX2,
                            DX3 = visit.DX3,
                            DX4 = visit.DX4,
                            DX5 = visit.DX5,
                            DX6 = visit.DX6,
                            IsDischarged = (visit.IsDischargedCode != null && visit.IsDischargedCode == "Y"),
                            PatientName = (visit.PatientFullName ?? visit.PatientLastName + ", " + visit.PatientFirstName),
                            PatientVisitId = visit.PatientVisitId,
                            PatientId = visit.PatientID,
                            PrimaryCarePhysician = visit.PrimaryCarePhysician,
                            Site = visit.Site,
                            Team = visit.Team
                        }
                    }
            ));

Answer 1

正如我期望的那样，您可以在一个查询中更有效地做到这一点：

from visit in dbContext.AV
where (visit.BFlag == null || visit.BFlag != "BI")
   && patientVisitIds.Contains(visit.PatientVisitId)
orderby visit.PatientVisitId
select new VisitBillTO
{
    Bed = visit.Bed,
    ...
    Team = visit.Team,
    Bills = (from bill
            in visit.Bills
            select new BillTO
            {
                Date = bill.Date.GetValueOrDefault(DateTime.Today),
                DoctorName = bill.DoctorName,
                Type = bill.Type,
                Encounter = bill.Encounter,
                CptCode = bill.CptCode
            })
}

现在，数据库完成了合并对象的所有繁重工作。一切都一应俱全。

请注意，我假设导航属性visit.Bills存在。这些属性通常存在于LINQ-to-SQL上下文中，但是由于某些原因在设计器中默认情况下它们始终处于折叠状态，因此人们倾向于忽略它们。如果由于某种原因该物业不存在，您可以替换...

Bills = (from bill in visit.Bills

通过...

Bills = (dbContext.ABills where visit.PatientVisitId == bill.PatientVisitId

减少LINQ查询时间

1 个答案: