LINQ到SQL的Int16被转换为的Int32在SQL命令

问题描述

使用方法参数

  Int16的？ ID 
  

而LINQ to SQL的where子句

 在哪里！id.HasValue || m.Id ==编号
  

在数据上下文的条件将所得命令文本是

从可视化：

  SELECT [T0] [ID]，[。 T0]。[名]，[T0]。[IsActive] 
从[产品型号] AS [T0] 
 WHERE（CONVERT（智力，[T0]。[ID]））= @ P0 
 ------------------------------- 
 @ P0 [的Int32]：5 
  

我的映射类具有ID作为Int16的和本身所具有的列类型为SMALLINT数据库中，那么，为什么后面的场景sql中认为参数是一个整数（Int32）已而不是SMALLINT（Int16的）？

---

列映射：

  [列（IsPrimaryKey =真，的DbType =SMALLINT NOT NULL，CanBeNull = FALSE）] 
公众的Int16标识{搞定;组; } 
  

解决方案

更改where子句来读

 在哪里！id.HasValue || m.Id == id.Value 
  

有一些是关于是把它扔了可空做空。我不知道为什么，但我之前就遇到了这个发现将 .value的将工作。

With the method parameter

Int16? id

And the Linq to SQL where clause

where !id.HasValue || m.Id == id

The resulting command text for the condition in the data context is

From the visualizer:

SELECT [t0].[Id], [t0].[Name], [t0].[IsActive]
FROM [Model] AS [t0]
WHERE (CONVERT(Int,[t0].[Id])) = @p0
-------------------------------
@p0 [Int32]: 5

My mapped class has the Id as an Int16 and the database itself has the column type as a smallint, so why does the behind the scenes sql think the parameter is an integer (Int32) and not a smallint (Int16)?

---

Column mapping:

    [Column(IsPrimaryKey = true, DbType="SmallInt NOT NULL", CanBeNull=false)]
    public Int16 Id { get; set; }

解决方案

Change the where clause to read

where !id.HasValue || m.Id == id.Value

There is something about the nullable short that is throwing it off. I'm not sure why, but I ran into this before and found adding .Value will work.

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