Question

所以我在ef核心中有一个以下查询，这导致重复的结果甚至很难我首先调用或默认它

DateTime maxDate = SqlDateTime.MaxValue.Value;
var results = (from r in _dbContext.audit_Results
                join e in _dbContext.audit_DataEncounters on new { r.IdAudit, r.PatientFirstName, r.PatientLastName, r.PatientDOB } equals new { e.IdAudit, PatientFirstName = e.FirstName, PatientLastName = e.LastName, PatientDOB = e.DateOfBirth } into eJoin
                let e = eJoin.Where(it => it.StartDate <= r.TransactionDate && r.TransactionDate <= (it.EndDate ?? maxDate))
                            .OrderBy(it => it.Inpatient).OrderByDescending(it => it.StartDate)
                            .FirstOrDefault()
                where r.IdAudit == idAudit && r.PatientFirstName == "ERIC" && r.PatientLastName == "BROOKS"
                select new AuditResultBulkModel()
                {
                    IdResult = r.IdResult,
                    map_HasPatient = eJoin.Any(),
                    map_IdEncounter = e != null ? e.IdEncounter : (int?)null
                }).ToList();

生成的查询如下所示：

SELECT *
FROM [audit_Results] AS [r]
LEFT JOIN [audit_DataEncounters] AS [e] ON ((([r].[IdAudit] = [e].[IdAudit]) AND (([r].[PatientFirstName] = [e].[FirstName]) OR ([r].[PatientFirstName] IS NULL AND [e].[FirstName] IS NULL))) AND (([r].[PatientLastName] = [e].[LastName]) OR ([r].[PatientLastName] IS NULL AND [e].[LastName] IS NULL))) AND (([r].[PatientDOB] = [e].[DateOfBirth]) OR ([r].[PatientDOB] IS NULL AND [e].[DateOfBirth] IS NULL))
WHERE (([r].[IdAudit] = @__idAudit_1)
ORDER BY [r].[IdAudit], [r].[PatientFirstName], [r].[PatientLastName], [r].[PatientDOB]

有人可以告诉我如何从中得到正确的结果吗？

过去（.net Framework中的实体框架） - 这用于使用OUTER APPLY生成非重复结果。

编辑：我的EF Core版本是2.0.0。

数据模型如下：

public class audit_Result
{
    [Key]
    public int IdResult { get; set; }

    public int IdAudit { get; set; }

    public bool? map_HasPatient { get; set; }

    public int? map_IdEncounter { get; set; }        

    public virtual audit_Audit audit_Audit { get; set; }
}

public class audit_DataEncounter: IAuditEntity
{
    [Key]
    public int IdEncounter { get; set; }

    public int IdAudit { get; set; }

    [StringLength(50)]
    public string FirstName { get; set; }

    [StringLength(50)]
    public string LastName { get; set; }

    public DateTime? DateOfBirth { get; set; }

    public DateTime? StartDate { get; set; }

    public DateTime? EndDate { get; set; }

    public bool? Inpatient { get; set; }        

    public virtual audit_Audit Audit { get; set; }
}


public class audit_Audit
{
    [Key]
    public int IdAudit { get; set; }

    public virtual ICollection<audit_DataEncounter> audit_DataEncounters { get; set; }

    public virtual ICollection<audit_Result> audit_Result { get; set; }
}

Answer 1

不幸的是，EF Core查询翻译仍然是（截至目前为止的最新版本2.0）远远不是最好的。如果您打开EF Core日志记录，您将看到许多警告，表明某些表达式无法翻译并将在本地进行评估（所谓的客户评估）。

我可以为此特定查询建议的唯一解决方法是消除join和let语句并使用map_HasPatient和{{1}的子查询（具有重复的连接过滤条件）投影属性：

map_IdEncounter

转换为SQL查询，如下所示：

var results = (
    from r in _dbContext.audit_Results
    where r.IdAudit == idAudit && r.PatientFirstName == "ERIC" && r.PatientLastName == "BROOKS"
    select new AuditResultBulkModel
    {
        IdResult = r.IdResult,
        map_HasPatient = _dbContext.audit_DataEncounters
         .Any(e => r.IdAudit == e.IdAudit && r.PatientFirstName == e.FirstName && r.PatientLastName == e.LastName && r.PatientDOB == e.DateOfBirth),
        map_IdEncounter = _dbContext.audit_DataEncounters
             .Where(e => r.IdAudit == e.IdAudit && r.PatientFirstName == e.FirstName && r.PatientLastName == e.LastName && r.PatientDOB == e.DateOfBirth
                 && e.StartDate <= r.TransactionDate && r.TransactionDate <= (e.EndDate ?? maxDate))
             .OrderBy(e => e.Inpatient).ThenByDescending(e => e.StartDate)
             .Select(e => (int?)e.IdEncounter)
             .FirstOrDefault()

    }).ToList();

实体框架核心 - 在迁移到.net核心后首先返回重复的结果

1 个答案: