From: Warren Young
Date: April 17 2007 1:16am
Subject: Re: NULL in templatized queries
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Michael Hanselmann wrote:
> 
> A clean solution isn't possible without breaking compatibility; 

Just adding new functions shouldn't break anything.

> +SQLString::SQLString(const SQLNullStringTag& value) :

I don't see a need to invent a new type.  I think you can get the 
behavior you want by adding a conversion ctor to SQLString that takes a 
mysqlpp::null_type.  That ctor just evaluates to "NULL", ignoring the 
passed parameter's actual value.  To get a null template parameter, you 
simply pass mysqlpp::null.

Is that not sufficient?