[Zope] how to check if the ResultSet is null?

[slin@iastate.edu]

Hi, I still got problems after I changed my code according to your 
suggestion. Here is the detail describtion of my code:
In registration form, I have a table which contain a field usr_email 
     (<tr>
        <td width="40%" align="right">Email Address&nbsp; </td>
        <td width="60%"><input type="text" name="usr_email" size="20"></td>
      </tr>)
      
This form takes an action in which I have following lines:
<dtml-if search_membership>
<p>Your email address has been used. </p>
<dtml-else>
<dtml-call personinfo_insert>
<h2>Welcome <dtml-var name="usr_fname">! You became a new user.</h2> 
</dtml-if>

where "search_membership" is an ZSQL method (select usr_email
from personinfo
where usr_email = <dtml-var name="usr_email">) and "personinfo_insert" is 
a ZSQL method which insert the data to the table("personinfo")

My idea is first checking if usr_email is in the table, if so, do not 
insert, otherwise insert. If I just use <dtml-call personinfo_insert>, 
everything is fine. However, when I added the <dtml-if> as above, I got 
the following error:
Zope has encountered an error while publishing this resource. 

Error Type: KeyError
Error Value: usr_email

Could you help me out? Thanks!

Sa


> Hi,
> 
> > 
> > Hi, I stuck on a problem: I am creating a registration form. I need
> > to check if the person info has already in database. I created a Z SQL
> > method which I used "select usr_email from info(table name) where
> > usr_email = <dtml-sqlvar usr_email type=string>" I want to call this
> > method from my dtml method and see if it returns "null". But I'm not
> > sure how to implement this. In Java, it has ResultSet which I can
> 
> let's say, you called your ZSQL-method "getThisAddress"
> 
> then you can do something like this:
> 
> <dtml-if getThisAddress>
> 	You are already in the database
> </dtml-if>
> 
> Robert
> -- 
> Robert Wohlfahrt (robert.wohlfahrt@sachsen-net.com)
> Tel: 0179 / 2980074 Fax: 0351 / 2880145
>