Thanks very much ! that has been really helpful !<br><br>
<div class="gmail_quote">On Fri, Jun 20, 2008 at 2:24 PM, Michael Kay <<a href="mailto:mike@saxonica.com">mike@saxonica.com</a>> wrote:<br>
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<div dir="ltr" align="left"><span><font face="Arial" color="#0000ff" size="2">First point is that XQJ is an interface - a way that XQuery users can talk to XQuery implementations. It is not itself an XQuery implementation. XQJ is to Saxon as SQL is to relational databases.</font></span></div>
<div dir="ltr" align="left"><span><font face="Arial" color="#0000ff" size="2"></font></span> </div>
<div dir="ltr" align="left"><span><font face="Arial" color="#0000ff" size="2">><font face="Times New Roman" color="#000000" size="3">What I am also wondering is the extent to which products like datadirect Xquery have utilised the XQJ API to provide easy access to a relational database and how an XML view of a relational database can be derrived ? </font><br>
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<div dir="ltr" align="left"><span><font face="Arial" color="#0000ff" size="2">That's a question very specific to the DataDirect product. </font></span></div>
<div dir="ltr" align="left"><span><font face="Arial" color="#0000ff" size="2"></font></span> </div>
<div dir="ltr" align="left"><span><font face="Arial" color="#0000ff" size="2">><font face="Times New Roman" color="#000000" size="3">My only guess at the moment is that it makes an SQL call to retrieve all the column names and builds some sort of internal schema using this ?</font><br>
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<div dir="ltr" align="left"><span><font face="Arial" color="#0000ff" size="2">Well, I guess there's a lot more to it than that, but I expect you're along the right lines.</font></span></div>
<div dir="ltr" align="left"><span><font face="Arial" color="#0000ff" size="2"></font></span> </div>
<div dir="ltr" align="left"><span>>I'm I right in thinking that the XQJ API alone offers no such automatic connection to table columns in a non XML relational database.</span></div>
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<div dir="ltr" align="left"><span><font face="Arial" color="#0000ff" size="2">XQJ is just a pipe down which you can send XQuery requests. Unless there's someone listening at the other end, it can't do anything.</font></span></div>
<div dir="ltr" align="left"><span><font face="Arial" color="#0000ff" size="2"></font></span> </div>
<div dir="ltr" align="left"><span><font face="Arial" color="#0000ff" size="2">><font face="Times New Roman" color="#000000" size="3">If this is the case my questions is whether Saxon can be modified to do this (if at all advisable) and what work I would need to do to achieve this.</font><br>
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<div dir="ltr" align="left"><span><font face="Arial" color="#0000ff" size="2">It's possible in theory but it's a *very* significant amount of work - especially for someone who isn't already aware that it's a large project.</font></span><br>
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<div dir="ltr" align="left"><span><font face="Arial" color="#0000ff" size="2">><font face="Times New Roman" color="#000000" size="3">I noticed when playing with the evaluation version of DataDirect Xquery that it loaded what appears to be a saxon module </font></font></span></div>
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<div dir="ltr" align="left"><span><font face="Arial" color="#0000ff" size="2">DataDirect XQuery uses some component technology acquired from Saxonica. It does a lot more than Saxon (by distributing a query to multiple data sources and assembling the results), but it reuses some of the Saxon technology to do parts of the query processing.</font></span></div>
<div dir="ltr" align="left"><span><font face="Arial" color="#0000ff" size="2"></font></span> </div>
<div dir="ltr" align="left"><span><font face="Arial" color="#0000ff" size="2">Michael Kay</font></span></div>
<div dir="ltr" align="left"><span><font face="Arial" color="#0000ff" size="2">Saxonica</font> </span></div>
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<font face="Tahoma" size="2"><b>From:</b> <a href="mailto:talk-bounces@x-query.com" target="_blank">talk-bounces@x-query.com</a> [mailto:<a href="mailto:talk-bounces@x-query.com" target="_blank">talk-bounces@x-query.com</a>] <b>On Behalf Of </b>paul agbetile<br>
<b>Sent:</b> 20 June 2008 12:15<br><b>To:</b> <a href="mailto:talk@x-query.com" target="_blank">talk@x-query.com</a><br><b>Subject:</b> [xquery-talk] How do Java Xquery technologies fit ?<br></font><br></div>
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<div>Hi, I am about to embark on a project that will require me accessing XML sources as well as relational databases and would really appreciate some help in trying to navigate through alot of what has me confused.<br> <br>
Firstly I should mention I am new to XQJ and Xquery. I started a few days ago with Michael Kay's "Learn XQuery in 10 Minutes" tutorial which I found really helpful and have written a few queries since. <br>I am struggling to understand where XQJ ends and products like Saxon and datadirect Xquery begin. What I am also wondering is the extent to which products like datadirect Xquery have utilised the XQJ API to provide easy access to a relational database and how an XML view of a relational database can be derrived ? <br>
My only guess at the moment is that it makes an SQL call to retrieve all the column names and builds some sort of internal schema using this ?<br> <br>I'm I right in thinking that the XQJ API alone offers no such automatic connection to table columns in a non XML relational database. If this is the case my questions is whether Saxon can be modified to do this (if at all advisable) and what work I would need to do to achieve this.<br>
<br>At present my assumptions range from having to write my own JDBC driver (that can generically talk to several databases) as well as devising some sort of Xquery to SQL translation. I noticed when playing with the evaluation version of DataDirect Xquery that it loaded what appears to be a saxon module ? This again has me confused as to how all these technologies fit in with one another.<br>
<br>Thanks,</div>
<div>Paul</div></blockquote></div></blockquote></div><br>