Re: Microsoft C++ Exception std::out_of_range mysql-connector-c++-8.0.18-winx64

[Rand Olmsted]

I buillt 8.0.18 from source with openssl (also build from source) statically linked. I had to use Visual Studio 2017 for the build. Visual Studio 2019 gave an error that mysqlx_row_struct could not be found. I build with this cmake invocation, followed by using the Visual Studio solution > project ALL_BUILD.

cmake -Wno-dev -B .\. -S .\.. -G "Visual Studio 15 2017 Win64" -DBUILD_STATIC=ON -DWITH_DOC=ON -DCMAKE_INSTALL_PREFIX=..\..\mysql-connector-cpp-8.0.18\lib -DWITH_SSL=..\..\..\openssl-1.1.1d\lib --loglevel=STATUS --check-system-vars

I am now able to step through all of the connector code.

When attempting to read the database the standard library <map> throws std::out_of_range from "_NODISCARD mapped_type& at(const key_type& _Keyval)". _Keyval is 0.
The calling location is in reslut.h function "Value& get(col_count_t pos)". pos is 0. Line of code that throws: "return m_vals.at(pos);"
The exception is not fatal and the returned result (a pair of strings, one of which is a path to a file) works to open the file without error.

code to reproduce the error (I tried to mirror what I have in the real app as much as possible):

#include <mysqlx/xdevapi.h>
#include <string>
using namespace ::mysqlx;
#define DATABASE_URL L"mysqlx://test_operator:2694@localhost:33060"
#define DATABASE_SCHEMA_CONFIGURATION L"test_stand_configuration"
int main( int argc, char** argv )
{
Session session( DATABASE_URL );
RowResult result;
Row row;
Value value;
size_t row_count = 0;
std::vector<std::wstring> paths;
std::wstring path_id;
std::wstring path;
try
{
result = session.getSchema( DATABASE_SCHEMA_CONFIGURATION )
.getTable( L"image_resource_list" )
.select( L"resource_id", "name" )
.execute();
row_count = result.count();
if( row_count > 0 )
{
row = result.fetchOne();
while( !row.isNull() )
{
value = row[0]; // throws nonfatal std::out_of_range
path_id = static_cast<std::wstring>( value );
value = row[1]; // throws nonfatal std::out_of_range
path = static_cast<std::wstring>( value );
std::wcout << L"Path ID: " << path_id << L" Path: " << path << std::endl;
row = result.fetchOne();
}
}
}
catch( std::exception& e )
{
cout << "Exception Message: " << e.what() << endl;
}
catch( ... )
{
cout << "UNKNOWN exception caught" << endl;
}
}

Table being read:

CREATE TABLE `image_resource_list` (
`resource_id` varchar(45) CHARACTER SET utf8mb4 COLLATE utf8mb4_bin NOT NULL,
`name` varchar(260) CHARACTER SET utf8mb4 COLLATE utf8mb4_bin NOT NULL,
PRIMARY KEY (`resource_id`),
UNIQUE KEY `resource_id_UNIQUE` (`resource_id`),
UNIQUE KEY `name_UNIQUE` (`name`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin COMMENT='List of application image resources keyed to a resource id';