Question

我已经看到了几个StackOverflow问题，但它们似乎与我的情景不符。我保证我看了。

我对我的数据库有一些查询，我正在使用linq来做，我无法弄清楚为什么生成了错误的SQL。这在我的代码中的几个地方发生。我希望我们只是陷入一些众所周知的陷阱，但我无法理解为什么Linq似乎决定我的where子句是愚蠢的，不应该将它添加到生成的SQL查询中。

为什么会这样？

示例：

var testing = (from i in context.TableName1 where i.Param1 == object1.GuidParam select i).ToList();

以上查询返回以下SQL

{SELECT 
    [Extent1].[RecordId] AS [RecordId], 
    [Extent1].[AnotherId] AS [AnotherId], 
    [Extent1].[YetAnotherId] AS [YetAnotherId], 
    [Extent1].[WeLikeIds] AS [WeLikeIds], 
    [Extent1].[WeReallyLikeIds] AS [WeReallyLikeIds]
    FROM [dbo].[SomeTable] AS [Extent1]}

但是以下查询：

var testing = (from i in context.TableName1 where i.Param1 == object1.GuidParam select i);
var testingToList = testing.ToList();

生成以下正确的SQL

{SELECT 
    [Extent1].[RecordId] AS [RecordId], 
    [Extent1].[AnotherId] AS [AnotherId], 
    [Extent1].[YetAnotherId] AS [YetAnotherId], 
    [Extent1].[WeLikeIds] AS [WeLikeIds], 
    [Extent1].[WeReallyLikeIds] AS [WeReallyLikeIds]
    FROM [dbo].[SomeTable] AS [Extent1]
WHERE [Extent1].[RecordId] = '78e49f5c-0ff8-e311-93f4-00155d514a6d'}

Answer 1

我更喜欢lambda符号，我不明白为什么这不会起作用......

var testing = context.TableName1.Where(i => i.Param1 == object1.GuidParam).ToList();

更清洁，简洁，它应该有用。

Linq为什么忽略我的where子句？

1 个答案: