C/c ++ to be continued dynamic memory and SQL Injection

SQL attacks are not implemented by using Operating System bugs, but by using the programmer's negligence and using SQL statements to achieve account-less login, even common memory errors in database tampering and Countermeasures 1 memory allocation is successful but it is used (accert is null) 2 memory allocation is successful, but it is referenced before initialization (error cause: first, there is no initialization concept; second, it is assumed that the initialization is completely zero, leading to a reference error (such as an array). 3. The memory is allocated successfully and has been initialized, however, operations go beyond the memory boundary. For example, when an array is used, the memory is often released when the subscript is 1 or 4 Less, leading to memory leakage. Malloc and free must be paired to use 5 to release the memory but continue to use it. There are three situations: the call relationship in program A is too complex. The return Statement of function B is wrong. (stack memory) after C releases the memory using free or delete, if the pointer is not set to NULL, the pointer is set to NULL immediately after the memory is released to prevent "Wild Pointer"