Of course, as always happens, I realize what I have done wrong
immediately after asking the question. I guess SSQLS expects the
results of the query to match the _whole_ list of fields presented in
the declaration. I would only use the SSQLS stuff when I am retrieving
whole records, not a single field like I am doing in the code I posted.
Thanks for your help. ;-)
Rick
Rick Gutleber wrote:
> Hi:
>
> I inherited a project that uses mysql++ as part of a larger C++ class
> library that was meant to incorporate other databases. Since we no
> longer require such support, I'd like to trim out the tons of overhead
> that "generic" database support required and basically migrate back to
> using mysql++ straight.
> I think SSQLS would fit the bill nicely, but I'm trying a trivial
> example and am getting a confusing error:
>
> Here is my table DDL:
>
> CREATE TABLE `data5m` (
> `interfaceID` int(11) NOT NULL,
> `sampleDate` datetime NOT NULL,
> `field`
>
> enum('ifOutErrors','ifOutDiscards','ifInDiscards','ifInErrors','ifHCInOctets','ifHighSpeed','ifSpeed','ifOperStatus','ifAdminStatus','ifOutOctets','ifInOctets')
>
> NOT NULL,
> `min` bigint(20) NOT NULL,
> `max` bigint(20) NOT NULL,
> `average` bigint(20) NOT NULL,
> KEY `sampleDate` (`sampleDate`),
> KEY `interfaceID` (`interfaceID`)
> ) ENGINE=InnoDB DEFAULT CHARSET=latin1;
>
> Here is my SSQLS declaration:`````
>
> sql_create_6( data5m, 1, 0,
> int, interfaceID,
> mysqlpp::DateTime, sampleDate,
> std::string, field,
> mysqlpp::sql_bigint, min,
> mysqlpp::sql_bigint, max,
> mysqlpp::sql_bigint, average
> )
>
> and the relevant code in my little experiment is this:
>
> mysqlpp::Query query = con.query( );
> query << "SELECT MIN( sampleDate ) FROM data5m";
>
> vector< data5m > result;
> query.storein( result );
>
> if ( result.size( ) == 0 ) {
> cout << "Nothing found!" << endl;
> } else {
> mysqlpp::DateTime dt = result[ 0 ].sampleDate;
>
> cout << dt.year << "-" << dt.month << "-" <<
> dt.day << " "
> << dt.hour << ":" << dt.minute <<
> ":" << dt.second << endl;
> }
>
> The error message, which happens on the storein( ) call, is confusing,
> and there must be some simple but non-obvious reason I am getting it:
>
> Conversion error: Bad type conversion: "2008-04-20 22:35:00"
> incompatible with "i" type
> retrieved data size: 4, actual size: 18
>
> Can anyone explain what might be going on here? I also tried it with
> mysqlpp::sql_datetime, but got the same results.
>
> Thanks,
>
> Rick
>
>
>
