我试图通过在一次访问数据库中包含子属性来提高我的 Linq-to-SQL 查询的效率。我首先尝试了各种 linq 查询来实现这一点。查询变得越来越复杂，所以我尝试了 LoadWith() 选项：
我的 DAL 类的构造函数设置了 LoadWith() 设置：
public TrackerJobData()
{
dataLoadOptions = new DataLoadOptions();
dataLoadOptions.LoadWith<TrackerJobRecord>(x => x.SpecBarcodeRecords);
dataLoadOptions.LoadWith<TrackerJobRecord>(x => x.TrackerJobEquipmentTriggerRecords);
dataLoadOptions.LoadWith<TrackerJobRecord>(x => x.EtaRecord);
this.Database.LoadOptions = dataLoadOptions;
}
这是我正在使用的查询：
public TrackerJob GetItem(int trackerJobId)
{
TrackerJobRecord record =
(from trackerJob in this.Database.TrackerJobRecords
where trackerJob.TrackerJobId == trackerJobId
select trackerJob).FirstOrDefault();
return record.Map();
}
当我仅在 linq 查询（而不是返回）上调试和 F10时，我在 SQL Profiler 中得到以下输出：
请原谅我对 SQL Profiler 的无知，但突出显示的三行是否意味着从客户端（我的代码）到服务器的三个往返行程？如果是这样，为什么？SQL Server 会一次执行多个 sp_executesql 调用吗？
而且由于我认为 LoadWith() 会消除多次调用，所以我做错了什么？
编辑
以下是 SQL Profiler 中的三个语句：
exec sp_executesql N'SELECT TOP (1) [t0].[TrackerJobId], [t0].[Name], [t0].[EtaId], [t0].[SamplingProcessorTypeId], [t0].[Description], [t0].[LastModifiedUser], [t0].[LastModifiedTime], [t0].[VersionNumber], [t0].[Active], [t0].[Archived], [t1].[EtaId] AS [EtaId2], [t1].[EtaNumber], [t1].[Title], [t1].[State], [t1].[DateInitialized], [t1].[EtaOriginatorId], [t1].[Quantity], [t1].[Ehs], [t1].[Ship], [t1].[InternalUse], [t1].[DateClosed], [t1].[ExperimentId], [t1].[Disposition], [t1].[TestType], [t1].[LastModifiedUser] AS [LastModifiedUser2], [t1].[LastModifiedTime] AS [LastModifiedTime2], [t1].[VersionNumber] AS [VersionNumber2]
FROM [AutoTracker].[TrackerJob] AS [t0]
INNER JOIN [Global].[Eta] AS [t1] ON [t1].[EtaId] = [t0].[EtaId]
WHERE [t0].[TrackerJobId] = @p0',N'@p0 int',@p0=17
exec sp_executesql N'SELECT [t0].[SpecBarcodeId], [t0].[TrackerJobId], [t0].[EquipmentId], [t0].[StartTime], [t0].[EndTime], [t0].[LastModifiedUser], [t0].[LastModifiedTime], [t0].[VersionNumber]
FROM [AutoTracker].[SpecBarcode] AS [t0]
WHERE [t0].[TrackerJobId] = @x1',N'@x1 int',@x1=17
exec sp_executesql N'SELECT [t0].[TrackerJobId], [t0].[EquipmentId], [t0].[LastModifiedUser], [t0].[LastModifiedTime], [t0].[VersionNumber]
FROM [AutoTracker].[TrackerJobEquipmentTrigger] AS [t0]
WHERE [t0].[TrackerJobId] = @x1',N'@x1 int',@x1=17