On Wednesday, May 1, 2013 at 11:42 AM, RJ Ryan wrote:
>On Wed, May 1, 2013 at 2:15 PM, Daniel Schürmann wrote:
>>Yes, we should solve this issue and use the const values in any case.
>>This allows to rely on IDE features like "display call tree".
>
>I think we should stick with whatever makes the code easiest to
>maintain (which would be using the constants when possible) -- maybe
>the constants should be renamed to be a little easier on the eyes? A
>lot of the DAO code doesn't use the constants, that's true. We should
>fix those queries.
Oy...OK. I'll keep the source-code comment with the human-readable version,
just to make it easier to understand.
>>But I am not sure if the use of const QString is performance neutral
>>to const char* and #define because the heavy QSting constructor is
>>called.
>>
>>So IMHO we should change it to const char*.
From what I've seen, the table names are #define'd strings, and the column
names are global QString objects. Seems like we should have one way to do
this. I'd prefer #define'd strings, simply because the compiler can optimize
this easily. If the compiler can optimize "const char *" just as well, let's
do that instead.
I try to make sure my code runs well on low-end hardware (a side effect of
programming video-game consoles for so many years... :-)
>There are a lot of non-performance-neutral choices we make in Mixxx,
>but that alone isn't enough to make a decision, we have to take the
>context into account. Compared to the QSqlQuery::exec() that comes
>immediately after all these queries, some string concatenation isn't
>going to break the bank, cycle-wise. Processors are pretty good at
>memcpy these days :).
That's fine until we try to run Mixxx on a GP2X. :-)
On Wednesday, May 1, 2013 at 12:07 PM, RJ Ryan wrote:
>I would prefer we totally got rid of writing SQL queries directly in
>code and instead composed them using declarative C++ classes which are
>then compiled down to SQL.
That's one thing I really like about C# 3.0 ... the introduction of LINQ. So
much programming revolves around database queries; it's hard to believe that
it's taken this long for database-queries to become a first-class member of the
language, or that only one language has figured this out so far.
Steven Boswell
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