C# 单元测试EntityFramework中的DbFunctions中的函数
C# 单元测试中mock EntityFramework中的DbFunctions中的函数
1. 写一个挡板类来提供C#代码的实现
2. 在运行时，如果是LINQ to ENTITY，EF会忽略c#的实现而选择[DbFunction()]的定义，对于本例，SQL PROFILER抓到的sql如下：
1. 写一个挡板类来提供C#代码的实现
public static class DbFunctionUnitTestable
{
/// <summary>
/// This is for Unit Test.
/// When Running against DB ,EF will generate the SQL and ignore the implemenation
/// in this method . when calling from C#(Unit test) , will exeucte the logic below
/// </summary>
/// <param name="dt"></param>
/// <returns></returns>
[System.Data.Entity.DbFunction("Edm", "TruncateTime")]
public static DateTime? TruncateTime(DateTime? dt)
{
if (dt.HasValue)
{
return dt.Value.Date;
}
return null;
}
}
2. 在运行时，如果是LINQ to ENTITY，EF会忽略c#的实现而选择[DbFunction()]的定义，对于本例，SQL PROFILER抓到的sql如下：
exec sp_executesql N'SELECT
...
FROM [dbo].[TKT_Ticket_Usage] AS [Extent1]
WHERE ([Extent1].[TicketCode] = @p__linq__0) AND (((convert (datetime2, convert(varchar(255), [Extent1].[UsageDate], 102) , 102)) = (convert (datetime2, convert(varchar(255), @p__linq__1, 102) , 102))) OR ((convert (datetime2, convert(varchar(255), [Extent1].[UsageDate], 102) , 102) IS NULL) AND (convert (datetime2, convert(varchar(255), @p__linq__1, 102) , 102) IS NULL)))',N'@p__linq__0 nvarchar(4000),@p__linq__1 datetime2(7)',@p__linq__0=N'72016122817373389038',@p__linq__1='2017-02-08 00:00:00'