T-SQL Tutorial

Insert XML into SQL table


This article shows how to insert XML into SQL table. When you want to store XML information in an SQL table, it is necessary for the table to contain an XML type column. The XML type column is declared when creating the table or later if the table already exists in the SQL Server database.


Example

To insert XML data into an SQL table, you can follow these steps:


1. Create a table in SQL Server

Create a table in SQL Server that has a column of data type XML to store the XML data. For example, let's create a table called MyXmlTable with a single column called XmlData of type XML:

CREATE TABLE MyXmlTable (
XmlData XML
);


2. Prepare the XML data

Prepare the XML data that you want to insert into the table. You can either write the XML data directly in your SQL query, or you can load it from a file or a variable in your programming language. For example, let's say you have the following XML data that you want to insert:

<person>
<name>John</name>
<age>30</age>
</person>


3. Write INSERT statement

Write an INSERT statement that specifies the XML data to insert into the table. Use the INSERT INTO keyword followed by the name of your table and the name of the column that stores the XML data. Then use the VALUES keyword followed by the XML data enclosed in single quotes. For example, the following SQL statement inserts the XML data above into the MyXmlTable table:

INSERT INTO MyXmlTable (XmlData)
VALUES ('<person><name>John</name><age>30</age></person>');


4. Execute the SQL statement

Execute the SQL statement to insert the XML data into the table. The inserted data can be queried and manipulated like any other data in the table. For example, to retrieve the XML data from the MyXmlTable table, you can use the SELECT statement and cast the XmlData column to a string using the value() method:

SELECT XmlData.value('(/person/name)[1]', 'VARCHAR(50)') AS Name,
XmlData.value('(/person/age)[1]', 'INT') AS Age
FROM MyXmlTable;

This statement retrieves the "name" and "age" elements from the XML data and returns them as separate columns in the result set. Note that the value() method returns the value of the specified XML element as a scalar value of the specified data type (in this case, a string and an integer).


Advantages of using an XML in an SQL table

XML data can be stored and queried in a structured way without the need for complex data normalization and joins.
XML data can be easily serialized and deserialized in various formats, such as JSON, CSV, or HTML.
XML data can be easily integrated with other XML-enabled applications and services, such as web services, SOAP, and REST APIs.
XML data can be easily transformed and validated using XSLT and XML schema technologies.
XML data can be easily indexed and searched using Full-Text Search and XQuery technologies.


Disadvantages of using an XML in an SQL table

XML data can consume more storage space than other data types, especially for large documents or documents with repetitive elements.
XML data can be more difficult to query and manipulate using traditional SQL queries and programming languages, such as T-SQL or C#.
XML data can be more prone to parsing errors and performance issues if not properly designed and optimized.


Overall, using an XML type column in an SQL table can be beneficial if the application requires storing and processing structured or semi-structured data in a flexible and scalable way. However, it is important to carefully consider the performance, storage, and compatibility implications of using XML data, and to properly design the database schema and queries to handle the XML data efficiently.