On 4/3/2011 5:33 AM, Raymond Boettcher wrote:
>
> should work:
> if(string(vbasketballevent[b]["tf_station_num"]) != mysqlpp::null )
If vbasketballevent is a mysqlpp::Result, there's no reason at all you
need to convert Result[][] to std::string here.
If it's an STL container of SSQLSes instead, the only reason you might
have had to do that is that your SSQLS wasn't defined using
mysqlpp::Null<T> wrappers on the columns that can contain SQL NULL.
That wasn't possible pre-MySQL++ 3.0, but it is now, so any reason you
had for doing that once has gone away.
Either way, the check against mysqlpp::null shouldn't need to go through
any explicit conversions. MySQL++ fully preserves NULL-ness on values
now if you use data types that can preserve it.
Getting back to Eric's issue, you are correct, Raymond, that comparing
to the C NULL constant is wrong, and that part of the fix is to compare
against MySQL++'s mysqlpp::null value.
> I even use
> mysqlpp::sql_int_unsigned, etc for some of my variables
Are you using mysqlpp::sql_int_unsigned_null, etc., too? That's
shorthand for mysqlpp::Null<sql_int_unsigned>, etc.
> trying to compare the information with C++'s int has also given me
> bad compile issues in the past. I'm not sure if this is still
> true...
Depending on the data types of the columns in use, yes, using the
lib/sql_types.h typedefs can give better results than using textbook C++
types. That header knows things about the MySQL C API and about the
platform MySQL++ was built on that aren't expressed in plain old C++
data types.
