public virtual size_t GetStringLength(const char * cname)

The number of bytes or characters required to hold the string returned by one of the GetString() methods, not including the null-terminator.

The following example demonstrates how to get the string length of a column:

len = result_set->GetStringLength( cid );
dst = new char[ len + 1 ];
result_set->GetString( cid, dst, len + 1 );

For wide characters, the usage is as follows:

len = result_set->GetStringLength( cid );
dst = new ul_wchar[ len + 1 ];
result_set->GetString( cid, dst, len + 1 );