SqlFunctions.Checksum如何获取可查询的校验和 [英] SqlFunctions.Checksum how to get checksum for queryable

问题描述

我正在试图弄清楚如何让这个sql equivelant：

I'm trying to figure out how to get this sql equivelant:

select checksum_agg(checksum(*)) from Foo

来自linq SqlFunctions。只要我知道列，我就能轻松获得一列的校验和。但是，我不会知道列名。所以我可以这样做：

From linq SqlFunctions. I'm able to easily get the checksum for one column, so long as I know the column. However, I won't know column names. So I can do something like:

SqlFunctions.ChecksumAggregate(Foo.Select(x => x.Id))

但这只是校验和一列，我必须知道列名。有没有办法像SQL语句一样校验集合？或者在不知道列名的情况下一次将校验和作为一列？

But that is only the checksum of one column, and I have to know the column name. Is there a way to checksum the collection like the SQL statement? Or to get the checksum a column at a time without knowing the column name?

推荐答案

您可以使用 ChecksumAggregate 方法。



就像这样：

You can use ChecksumAggregate method for this.

It's like this :

using (AdventureWorksEntities AWEntities = new AdventureWorksEntities())
{
    // SqlFunctions.ChecksumAggregate is executed in the database.
    decimal? checkSum = SqlFunctions.ChecksumAggregate(
        from o in AWEntities.SalesOrderHeaders
        select o.SalesOrderID);

    Console.WriteLine(checkSum);
}

欲了解更多信息，请查看：



http://msdn.microsoft.com/en-us/library /vstudio/dd456858(v=vs.100).aspx [ ^ ]



http://msdn.microsoft.com/en-us/library/vstudio/dd487151（v = VS.100）的.aspx [ ^ ]



我希望这会对你有所帮助。

For more info check this :

http://msdn.microsoft.com/en-us/library/vstudio/dd456858(v=vs.100).aspx[^]

http://msdn.microsoft.com/en-us/library/vstudio/dd487151(v=vs.100).aspx[^]

I hope this will help to you.

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