简单SQL代码上的分段错误（核心转储）

I get a “Segmentation fault (core dumped)” error on some simple C++ code. The error will accure when I use the variable result. What can cause this problem in this case? I know that something goes out of range, but how is it possible that result does? There are only 2 items in the database. I get a “Segmentation fault (core dumped)” erro