Hi Ayan,
Brad - i believe when you have a WHERE clause already specified,
you do not need to use "<dynamic>".
You're thinking is probably right on this, but I'll go ahead and be a
bit more explicit on the <dynamic> tag (hopefully I'm not hijacking
the thread too much here).
Let's suppose we have a query that *might* need a WHERE clause.
Here's an example:
SELECT ID, DESCRIPTION
FROM ITEMS
<dynamic prepend="WHERE">
<isNotEmpty property="id">
ID = #id#
</isNotEmpty>
</dynamic>
This query could be used with queryForObject() if I specify an ID.
This query could also be used with queryForList() when I don't.
Let's take the case where I do specify the ID. In this case, the
<isNotEmpty> would evaluate to true and the ID = #id# bit would be
rendered. Since there's content within the <dynamic> tag, iBATIS will
render the prepend="WHERE" part. So, we'd ultimately get:
SELECT ID, DESCRIPTION
FROM ITEMS
WHERE ID = ?
Now, on to queryForList() and no ID. The <isNotEmpty> would evaluate
to false and therefore ID = #id# will not be rendered. This will
leave the <dynamic> tag without any content of its own and, therefore,
the prepend="WHERE" will not be rendered, either. The result:
SELECT ID, DESCRIPTION
FROM ITEMS
Now, a further question: Can we nest <dynamic> tags? I'm still on
version 2.1.5 (yeah, a year and a half ago) and it didn't seem to
work.
Ted
