Re: [Cppcms-users] cppdb::statement.affected() usage?

[Artyom <art...@ya...>]

> Subject: Re: [Cppcms-users] cppdb::statement.affected() usage?
> 
> Thank you a lot for the clarification!
> 
> > Yes, number of affected rows  is number of rows affected by
> > statements like DELETE or UPDATE, the  behavior of  affected()
> > when using queries (like SELECT) is  undefined and may cause
> > exceptions.
> 
> It will save users much time  if this behavior is documented.
> 

It is documented the term "affected" is something known in general
for SQL handling.

> Also, it will be handy if the number of  selected rows (returned by libpq's  
> PQntuples()) is implemented in  either cppdb::statement or cppdb::result.  
> Without this feature, it  seems that iterating cppdb::result (by calling  
> next()) is the only  available way to know the number of selected rows.  
> Wrong?
> 

The problem is this is not always known as you get the data by iterating
over it so in some backends like sqlite3 you can know this only
after fully iterating the entire data set and somethimes it is not
so good idea.

So this option is not supported as in some cases the data is not fetched
in whole.

Artyom