Question

与DateTimeOffset.Date属性进行比较时，我们发现客户端与服务器端评估的结果不一致。

给出实体：

public partial class PreHire
{
    public int PreHireId { get; set; }
    public DateTimeOffset StartDate { get; set; }
}

以及以下逻辑：

DateTime startDate = DateTime.Now;

//Pulls preHire with a start date of '2019-11-25 14:42:54.0833333 +00:00'
PreHire clientComparePreHire = context.PreHire.Where(x => x.PreHireId == 22407).FirstOrDefault();
if(clientComparePreHire.StartDate.Date >= startDate.Date)
{
    Console.WriteLine("This works.");
}

List<PreHire> serverComparePreHires = context.PreHire.Where(q => q.StartDate.Date >= startDate.Date).ToList();
if(serverComparePreHires.Count == 0)
{
    Console.WriteLine("This doesn't. This shouldn't be empty.");
}

我们得到以下日志：

info: Microsoft.EntityFrameworkCore.Database.Command[20100]
      Executing DbCommand [Parameters=[], CommandType='Text', CommandTimeout='30']
      SELECT TOP(1) [p].[PreHireID], [p].[StartDate]
      FROM [TBL].[PreHire] AS [p]
      WHERE [p].[PreHireID] = 22407
This works.
info: Microsoft.EntityFrameworkCore.Database.Command[20100]
      Executing DbCommand [Parameters=[@__startDate_Date_0='2019-11-25T00:00:00' (DbType = DateTimeOffset)], CommandType='Text', CommandTimeout='30']
      SELECT [p].[PreHireID], [p].[StartDate]
      FROM [TBL].[PreHire] AS [p]
      WHERE CONVERT(date, [p].[StartDate]) >= @__startDate_Date_0
This doesn't. This shouldn't be empty.

这表明serverComparePreHires为空，但是如果我手动运行上述查询，则会得到预期的结果：

SELECT [p].[PreHireID], [p].[StartDate]
FROM [TBL].[PreHire] AS [p]
WHERE CONVERT(date, [p].[StartDate]) >= '2019-11-25T00:00:00'

PreHireID   StartDate
22407   2019-11-25 14:42:54.0833333 +00:00

总而言之，当处理此特定linq查询服务器端时，EF Core会生成一个有效的SQL查询，但无法返回匹配的PreHire条目。我在这里想念什么吗？根据我的研究，EF Core应该能够处理任何DateTime.Date查询。

其他详细信息

EF核心版本：3.0.0（与3.0.1相同的结果）
数据库提供者：Microsoft.EntityFrameworkCore.SqlServer
目标框架：.NET Core 3.0（从2.1迁移）
操作系统：Windows 10
IDE：Visual Studio 2019 16.3.7

EF Core 3.0在客户端和服务器端日期比较之间提供不一致的结果

0 个答案: