Re: Reverse engineering SQL

[BB <adamnt42@xxxxxxxxx>]

On 26/3/25 11:21 am, T Lee Davidson wrote:

> On 3/25/25 7:46 PM, BB wrote:
> > I think I have to manipulate the query string and eliminate the WHERE 
> > and ORDER BY clauses and add LIMIT=1 (to get a result back in my 
> > lifetime! several million records). Will reply if it works.
>
> Could you execute the full query and simply append a "WHERE 1<>1" to 
> the end? That gives the filed names (at least with the Sqlite driver).
Well, yes and no. Yes, it has the same effect as LIMIT=0 (which also 
works). No, I cant just stick it on the end as there may be other 
clauses following the WHERE. I like your idea better though as I think 
the database SQL optimiser wont object to LIMIT=0 and not return a 
cursor. I mean for postgres (and standard SQL) Limit=0 is a valid clause 
that is parsed, planned and returns an empty set, I don't know for other 
databases.

I have set up a form to display the query (i.e. the visible query at 
this end) and it works >90% of the time. It fails when the query uses 
stored functions that require real parameter values (as I'm not 
providing them). I have run it manually over ~50 known query examples on 
the live database with excellent outcomes. I will ask the DBA's if it 
possible that their functions could be set up with default values but I 
am not sure if I can convince them of the benefits. 😕 As a matter of 
fact, I'm not sure it is possible in SQL/pSQL.

continuing in the general direction of on

b