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From:gary clark Date:February 16 2007 5:53pm
Subject:Re: Column sizes
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Hey Warren,

I ran some tests and am a wee' bit confused on the
outcomes.

Basically I've been trying to track down a problem
which is causing a crash on a Windows XP box using
2.1.1 build.

I'm creating a table with two columns:

guid, VARCHAR(256)
messageData, VARCHAR(20000)

I then populate the table using row:

sql_create_2(clienttransfer,
             1,2,
             string,guid,
             string,messageData)

/**************************************/

clienttransfer row(guid,buffer);

try{
   mysqlpp::Query query = _con.query();
   query.insert(row);
   query.execute();
}
catch (const mysqlpp::Exception & er) {
   cout << "Bad Entry::"<<er.what() << endl;
   return 1;
}
return SUCCESS;
}

No problem so far. I examine the table and everything
is good.

The problem comes when I attempt to retrieve the data:

mysqlpp::Query query = _con.query();

query << "select * from clienttransfer";

vector<clienttransfer> res;
vector<clienttransfer>::iterator it;
query.storein(res);

The first time function is called all data is accessed
correctly. The second time I access it I get 
a crash. I'm storing 8500 bytes in the messageData
column.

at mysqlpp.Query.use(Query *, ResUse *, SByte *)
at mysqlpp.Query.storein_sequence(class
std::vector(struct clienttransfer,class
std::allocator<struct clienttransfer>>>

When I use 8000 bytes for messageData I dont see this
crash.

Ok, so I wanted to isolate the problem. Basically take
the essence of what I'm doing i.e adding and
retrieving the column data and push that into a
separate test project. 

I could not recreate the problem. However I think what
is happening is that the second time I access the
table something is not being freed and causing
the crash to happen. If anybody has some idea on how
to isolate the problem that would be great. Since I
dont see a leak, it looks to me like I'm hitting a
memory boundary or something is not being freed in
mysql after first obtaining the data? Any ideas on how
to tackle this would be greatly appreciated.

Thanks,
Garyc

--- Warren Young <mysqlpp@stripped> wrote:

> gary clark wrote:
> > Exceeding that limit caused it to break. 
> 
> You're going to have to provide a test case for
> this.  With this vague 
> report of yours, I don't even know what "it" is, or
> what constitutes 
> this "break".  I can think of a dozen questions I
> could ask to clarify 
> this, but I'd rather just see it here.
> 
> > Could somebody please enlighten me on the maximum
> > sizes of column types. 
> 
> MySQL++ imposes no explicit size limitations.  If
> something's breaking, 
> my instinct is that it's a MySQL limitation, or
> you're running out of 
> memory somewhere.  If you have the memory and MySQL
> allows you to store 
> it, MySQL++ should allow you to access it.
> 
> -- 
> MySQL++ Mailing List
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> 
> 

Thread
Two bugs in 2.2.0Joseph Artsimovich12 Feb
  • Column sizesgary clark12 Feb
    • Re: Column sizesWarren Young13 Feb
      • Re: Column sizesgary clark16 Feb
        • Re: Column sizesWarren Young16 Feb
          • Re: Column sizesgary clark16 Feb
            • UPDATE routine giving exceptiongary clark16 Feb
              • Re: UPDATE routine giving exceptionJonathan Wakely17 Feb
                • Re: UPDATE routine giving exceptiongary clark18 Feb
                  • Re: UPDATE routine giving exceptionJames Vanns19 Feb
                    • Re: UPDATE routine giving exceptiongary clark19 Feb
                      • Re: UPDATE routine giving exceptiongary clark23 Feb
                        • Re: UPDATE routine giving exceptionWarren Young23 Feb
                          • Re: UPDATE routine giving exceptiongary clark23 Feb
                            • Re: UPDATE routine giving exceptionWarren Young24 Feb
                              • Re: UPDATE routine giving exceptionIan Miller24 Feb
                              • Re: UPDATE routine giving exceptiongary clark24 Feb
                                • Re: UPDATE routine giving exceptiongary clark28 Feb
                                  • Re: UPDATE routine giving exceptionWarren Young1 Mar
                                    • Re: UPDATE routine giving exceptiongary clark1 Mar
                                    • Re: UPDATE routine giving exceptiongary clark19 Mar
                                      • Re: UPDATE routine giving exceptionWarren Young19 Mar
                                        • Re: UPDATE routine giving exceptiongary clark19 Mar
                                          • Re: UPDATE routine giving exceptionWarren Young19 Mar
                                            • Re: UPDATE routine giving exceptiongary clark20 Mar
  • Re: Two bugs in 2.2.0Warren Young20 Feb
    • Re: Two bugs in 2.2.0Joseph Artsimovich20 Feb
      • Re: Two bugs in 2.2.0Jonathan Wakely20 Feb
        • Re: Two bugs in 2.2.0Joseph Artsimovich20 Feb
          • Re: Two bugs in 2.2.0Jonathan Wakely20 Feb
            • Re: Two bugs in 2.2.0Joseph Artsimovich20 Feb
              • Re: Two bugs in 2.2.0Jonathan Wakely20 Feb
        • Re: Two bugs in 2.2.0Warren Young20 Feb