<?xml version="1.0" encoding="iso-8859-1"?>
<?xml-stylesheet href="../make-menu.xsl" type="text/xsl"?><html>
<head>
<this-is section="sql-extension" page="update" subpage=""/>
<!--
Generated at 2011-12-09T20:47:22.916Z--><title>Saxonica: XSLT and XQuery Processing: sql:update and sql:column</title>
<meta name="coverage" content="Worldwide"/>
<meta name="copyright" content="Copyright Saxonica Ltd"/>
<meta name="title"
content="Saxonica: XSLT and XQuery Processing: sql:update and sql:column"/>
<meta name="robots" content="noindex,nofollow"/>
<link rel="stylesheet" href="../saxondocs.css" type="text/css"/>
</head>
<body class="main">
<h1>sql:update and sql:column</h1>
<p><code>sql:update</code> performs an SQL UPDATE statement. This causes a set of rows to be selected from a given table; columns
identified in a child <code>sql:column</code> element are then updated with new values.</p>
<p>The attributes are as follows:</p>
<table>
<tr>
<td content="para">
<p>connection</p>
</td>
<td content="para">
<p>The database connection.
This is mandatory, the value is an expression, which must evaluate to a database connection
object as returned by <code>sql:connect</code>.</p>
</td>
</tr>
<tr>
<td content="para">
<p>table</p>
</td>
<td content="para">
<p>The table to be updated.
This is mandatory, and the value must be known statically (it cannot be defined as an attribute value template).</p>
</td>
</tr>
<tr>
<td content="para">
<p>where</p>
</td>
<td content="para">
<p>The conditions to be applied (the contents of the WHERE clause of the select statement).
This is optional, if present the value is an attribute value template whose value is a SQL conditional expression.
If omitted, all rows in the table are updated.</p>
</td>
</tr>
</table>
<p><code>sql:column</code> is used as a child element of <code>sql:update</code>, and identifies the name and value of a column
to be included in the UPDATE statement. The name of the column is identified by the <code>name</code> attribute,
the value may be indicated either by evaluating the expression contained in the <code>select</code> attribute, or
as the expanded contents of the <code>sql:column</code> element. The value is always interpreted as a String.
(Remember this is purely a demonstration of extensibility, in a real system there would be a need to
cater for SQL columns of other data types).</p>
<table width="100%">
<tr>
<td>
<p align="right"><a class="nav" href="delete.xml">Next</a></p>
</td>
</tr>
</table>
</body>
</html>
