title | description | author | ms.author | ms.reviewer | ms.date | ms.service | ms.subservice | ms.topic | helpviewer_keywords | |
---|---|---|---|---|---|---|---|---|---|---|
Columns that Contain a Null Value By Default |
Learn how to work with columns that contain a null value by default by using the ELEMENTS XSINIL keyword phrase in SQL. |
MikeRayMSFT |
mikeray |
randolphwest |
05/05/2022 |
sql |
xml |
conceptual |
|
[!INCLUDE SQL Server Azure SQL Database Azure SQL Managed Instance]
By default, a null value in a column maps to the absence of the attribute, node, or element. This default behavior can be overridden by using the ELEMENTS XSINIL keyword phrase. This phrase requests element-centric XML. This means that null values are explicitly indicated in the returned results. These elements will have no value.
The ELEMENTS XSINIL phrase is shown in the following Transact-SQL SELECT example.
SELECT EmployeeID as "@EmpID",
FirstName as "EmpName/First",
MiddleName as "EmpName/Middle",
LastName as "EmpName/Last"
FROM HumanResources.Employee E, Person.Contact C
WHERE E.EmployeeID = C.ContactID
AND E.EmployeeID=1
FOR XML PATH, ELEMENTS XSINIL;
The following shows the result. If XSINIL isn't specified, the <Middle>
element will be absent.
<row xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" EmpID="1">
<EmpName>
<First>Gustavo</First>
<Middle xsi:nil="true" />
<Last>Achong</Last>
</EmpName>
</row>