Re: [boost] [gsoc2008] Database Library (asynchronous)

From: Maciej Sobczak (prog_at_[hidden])
Date: 2008-03-25 13:18:54

Jeff Garland wrote:

>> 1) overloads of operator<< and operator,
>>   It confuses me to use operator<< to get information _out_ of
>>   something.
> 
> Ok, but I don't think SOCI does that.  It uses operator<< on an SQL
> statement to bind variables -- the variables can be input or output
> depending on what you're doing.

Well, not exactly. :-)

string name;
int id = ...;

sql << "select name from persons where id = :id", into(name), use(id);

Above:

- operator<< is used to *send* query to the server,
- "into element" is used to bind variable that will get results,
- "use element" binds variable that provides data for the query,
- operator, is used to bunch all parts of the query together.

In other words, operator<< is not used to "get something out" (into 
elements serve this purpose instead), but to "make things happen".

-- 
Maciej Sobczak * www.msobczak.com * www.inspirel.com