<p>I basically have an xml column, and I need to find and replace one tag value in each record.</p>

To find a content in an XML column, look into the exist() method, as described in MSDN
here
.
```
```
SELECT * FROM Table
WHERE XMLColumn.exist('/Root/MyElement') = 1
```
```
...to replace, use the modify() method, as described
here
.
```
```
SET XMLColumn.modify('
  replace value of (/Root/MyElement/text())[1]
  with "new value"
')
```
```
..all assuming SqlServer 2005 or 2008.  This is based on XPath, which you'll need to know.