Upayavira wrote:
Daniel Fagerstrom wrote:
...
Anyway, for the time beeing I think it is better to focus on making it
as easy as possible to use SQL from flowscripts and present the result
sets in CTemplate. Then if we don't get it easy enough we can start to
think about doing part of ESQL in CTemplate.
Whilst I'm not going to be the person implementing it, having seen the
distinction made between SELECT and UPDATE in ESQL/SQLTransformer, I'd
happily see tags added to CTemplate to allow for SQL querying, without
the ability to update/insert.
Surely the main thing about a template is that it is side-effect free,
and that would be.
Maybe better would be some way to separate the SQL from the template.
Imagine:
<esql:select name="my-query" idEmployee="#{request.getParameters('id')}/>
And queries.sql:
my-query: SELECT * FROM Employee WHERE idEmployee = ${idEmployee}
my-other-query: SELECT * FROM Employers
I guess you'd define your queries.sql file in the <map:generators>
section of your sitemap.
The worst thing about ESQL/SQLTransformer in my view is the embedded
SQL. Horrible.
That require a small string template language for the queries. While it
wouldn't be such a big deal to implement a such labuage I'm not to happy
with having several different template languages with different properties.
I'd rather have a script action that reuse the flow script mechanisms
except for the web continuation, (as Torsten discussed in another
thread). Then we could have some utility functions for making it easy to
create (lazy) query result sets that are embed in some suitable data
structure that make it easy to iterate over it from JXTG.
The script could look like:
// Query script
myResult = executeSelect("SELECT * FROM Employee WHERE idEmployee = ?",
{request.parameter.id});
myOtherResult = executeSelect("SELECT * FROM Employers");
return {"myResult": myResult, "myOtherResult": myOtherResult};
The return map from the script is supposed to be used with the ordinary
flow attribute mechanism from JXTG.
The template would do an ordinary for each:
<jx:for-each select="#{myOtherResult/row}">
<tr>
<td>#{name}</td>
<!-- ... -->
</tr>
</jx:for-each>
Simple and respects SoC, IMO.
/Daniel
