For the SQL query, nothing more than a SELECT:

SELECT id, info from client

Easy, but not really powerful for XML data, let’s try with XQuery, who give us two functions for DB2. db2-fn:sqlquery and db2-fn:xmlcolumn. The first function retrieves a sequence that is the result of an SQL fullselect and the second retrieves a sequence from a column. One important thing you should keep in mind, SQL is not a case-sensitive language alors que XQuery is a case-sensitive language.

An example which return all the XML data from the “info” column:

XQUERY db2-fnxmlcolumn ('CLIENT.INFO')

Which is same as this SQL query:

SELECT info FROM client

Let’s see something more nice. This query will return all the elements in <name> , inside the “info” column, and with the <city> element which containt “Paris”:

XQUERY declare defaut element namespace "http://posample.org";
for $d in db2-fn:xmlcolumn('CLIENT.INFO')/clientinfo
  where $d/addr/city="Paris"
return <out>{$d/name}</out>

db2-fn:xmlcolumn retrieves the data from the “info” column in the “client” table. We add a $d variable, for each element of <clientinfo>, and we use a where to filter the <city> element which should be “Paris. To finish, we use <out> to output the data:

<out xmlns="http://posample.org">
  <name>Sophie Bool</name>
</out>

XQUERY declare default element namespace "http://posample.org";
for $d in db2-fn:sqlquery('SELECT info FROM client')/clientinfo
  where $d/addr/city="Paris
return <out>{$d/name}</out>