如何使用Linq to SQL以XML列（作为字符串）查询SQL Server表？

Question

How can I use LINQ to SQL to query a table with an XML datatype column as an IQueryable?

SQL Server table:

Id [int]
SomeData [xml]

An example of SomeData could be:

<container><Person>Joe Smith</person></container>

In T-SQL, I can query the table like this to find employees with a specific nam,e :

SELECT 
    *
FROM
    [MyTable]
WHERE 
    SomeData.value('(//*[local-name()="Person"])[1]', 'varchar(max)') = 'Joe Smith'

Or to treat the xml as a string, to search for a string regardless of xml schema:

SELECT 
    *
FROM
    [MyTable]
WHERE 
    CONVERT(varchar(max), SomeData) like '%Joe Smith%'

Now I turn to LINQ to SQL, and want to perform the second query:

var myTable = db.MyTable.Where(x => x.SomeData.Value.Contains("Joe Smith"));

I get the error:

"The member 'System.Xml.Linq.XElement.Value' has no supported translation to SQL.

I understand why I get the error, but is there a way to work around it?

Being able to query the column as a string (with no concept of xml-structure) is completely fine in this case.

Answer 1

创建一个将Xml列公开为varchar（...）并查询它的视图。

Answer 2

您可以使用System.Data.Linq.SqlClient.SqlMethods.Like（）代替Contains。

var myTable = db.MyTable.Where(x => SqlMethods.Like(x.SomeData, "%Joe Smith%"));

Answer 3

将xml文件导入带有xml列的临时表，然后尝试解析该文件并将其放入关系表中。