[odb-users] how to blob an array of float in mysql with odb 2.4.0?

不明真相 icewill9999 at vip.qq.com
Tue Jun 22 03:26:07 EDT 2021

Hi, Boris,
 I have an array of float values and I need to store them into mysql BLOB column, I defined the mapping as below:
typedef std::vector<unsigned char&gt; buffer; #pragma db value(buffer) type("BLOB")
#pragma db section(extras_)    buffer log_data_; // use the section to load the BLOB data
I convert the array of float values into a vector of unsigned char and then store them into the BLOB column. When I read the stored BLOB and convert them back I found only the 64 float values from beginning are correct, which I think is the default size of details::buffer. 
I dug into the odb generated file -odb.cxx, and found the size of buffer was never grown to meet the large size// log_data_    //    if (t[11UL])    {      i.log_data_value.capacity (i.log_data_size);      grew = true;    }so I add the code    if(i.log_data_size &gt;256) t[11UL] =1; it's worked, but all the converted values are wrong.
Is it a bug of ODB 2.4.0 or I did something wrong? please guide me with this, thanks.
Best Regards,Wang

More information about the odb-users mailing list