Length of the blob received by "select"

[YukunXia]

Hi Roland,

First of all, thank you so much for writing and maintaining such an awesome library!

I have a question about the mechanism of receiving objects with dynamic length. Specifically, let's say, the blobs. Sending a std::vector<uint8> to a key foo is straightforward. But as I tried to read the same content back via select, there were two seemingly equivalent ways, either blob with len, or simply value(). In the test with sqlite3 and pgsql, blob with len is used, rather than value(), Is there any particular reason why this version is preferred?

Best,
Yukun

[rbock]

Hi Yukun,

Thanks for the praise :-)

And thanks for the question, of course. Both variants work just fine. value() returns a copy of the value, though.

Background:
In the early days, I decided to return a default-constructed value if you asked for the value of a NULL result. From today's perspective, that was probably a mistake. Every now and then I am thinking of changing that, but it is hard to do so without breaking everybody.

Cheers,
Roland

[YukunXia]

Thank you for the timely reply! Now I understand it much better :)