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我给出了一个简单的 EF 查询

return context.GlobalEntities
.Where(ge => ge.IsActive == true)  
.ToList()

它被翻译成以下 SQL 查询

SELECT 
[Extent1].[GlobalEntityId] AS [GlobalEntityId], 
[Extent1].[GlobalEntityName] AS [GlobalEntityName], 
[Extent1].[GlobalEntityAlias] AS [GlobalEntityAlias], 
[Extent1].[GlobalEntityTypeId] AS [GlobalEntityTypeId], 
[Extent1].[IsActive] AS [IsActive], 
[Extent1].[CreatedBy] AS [CreatedBy], 
[Extent1].[CreatedAt] AS [CreatedAt], 
[Extent1].[ChangedBy] AS [ChangedBy], 
[Extent1].[ChangedAt] AS [ChangedAt], 
[Extent1].[EmailAddress] AS [EmailAddress], 
[Extent1].[AverageActionTimeInHrs] AS [AverageActionTimeInHrs], 
[Extent1].[AverageCreationTimeInHrs] AS [AverageCreationTimeInHrs]
FROM [dbo].[GlobalEntity] AS [Extent1]
WHERE 1 = [Extent1].[IsActive]

当我执行上面的代码时，它需要 45 秒才能执行，而当我从 SSMS 执行相同的查询时只需要 1 秒。

关于为什么实体框架执行简单查询需要这么长时间的任何想法。这是 SQL 探查器所说的

SQL:BatchCompleted  SELECT 
[Extent1].[GlobalEntityId] AS [GlobalEntityId], 
[Extent1].[GlobalEntityName] AS [GlobalEntityName], 
[Extent1].[GlobalEntityAlias] AS [GlobalEntityAlias], 
[Extent1].[GlobalEntityTypeId] AS [GlobalEntityTypeId], 
[Extent1].[IsActive] AS [IsActive], 
[Extent1].[CreatedBy] AS [CreatedBy], 
[Extent1].[CreatedAt] AS [CreatedAt], 
[Extent1].[ChangedBy] AS [ChangedBy], 
[Extent1].[ChangedAt] AS [ChangedAt], 
[Extent1].[EmailAddress] AS [EmailAddress], 
[Extent1].[AverageActionTimeInHrs] AS [AverageActionTimeInHrs], 
[Extent1].[AverageCreationTimeInHrs] AS [AverageCreationTimeInHrs]
FROM [dbo].[GlobalEntity] AS [Extent1]
WHERE 1 = [Extent1].[IsActive]  

Application Name: EntityFramework   
NTUserName: user
CPU: 187    
Reads: 1357 
Writes: 0   
Duration: 45157 
ProcessID: 9520 
StartTime: 2012-07-06 10:38:40.797  
End TIme: 2012-07-06 10:39:25.953
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