core/statement.cpp : Modified to support complex queries

[JoshuaVThomas]

Added a part where describe is called again if numcols doesn't get populated before execution of query.

Ref : #1151

[vadz]

Thanks, but it would be possible to add a test case that fails now but would work with this change? Otherwise this risks getting broken again in the future.

[vadz]

Sorry, I really can't merge without understanding what exactly this fixes.

[JoshuaVThomas]

Hi @vadz I've added the test case where this failed but succeeds now.

[vadz]

Thank you, but I'll need some help with understanding what exactly happens with this query... Any extra explanations would be welcome!

[JoshuaVThomas]

This is a sample query which has a CURSOR declared. It's aim is to execute a complex query at ones instead of set by set operation. Since it's a complex query it takes some time to execute so that the numcols doesn't get set. So the code has been modified to address this.

[vadz]

Sorry for the delay, I've finally looked at it and I couldn't find any better way to fix this than to apply almost this change, please see #1182 which I've created to replace this one.

The main difference is that I don't understand how did it work for you, and even in the CI build, without calling define_for_row() after the 2nd describe(). In my local testing this just crashed because intosForRow_ elements were never initialized and, again, I just don't see how could it work without it.

Anyhow, if you don't have any objections to calling define_for_row() too, I'll merge the other PR soon.

Thanks again for the fix!