Mysql c++ connector, cannot create column by code - c++

Question

I am doing kind of password manager, when I try to delete some entry ids are placed wrong
For instance, ids are place like ...19,20,21... >> deleted 20 >> ...19,21,22...
The only way to fix it, that I found was deleting and creating back id column.
The part of deleting a column works fine, but creating it back though doesn't work.
Here is my code
#include <iostream>
#include <mysql/mysql.h>
#include <mysql_connection.h>
#include <cppconn/driver.h>
#include <cppconn/exception.h>
#include <cppconn/resultset.h>
#include <cppconn/statement.h>
using namespace std;
int main(){
sql::Driver *myDriver; //connecting an SQL
sql::Connection *myConn;
sql::Statement *myStmt;
sql::ResultSet *myRes;
myDriver = get_driver_instance(); // connecting to db
myConn = myDriver->connect("localhost", "root", "password");
myConn->setSchema("passwords");
myStmt = myConn->createStatement(); // deleting id column
myRes = myStmt->executeQuery("ALTER TABLE password_table DROP id;");
myStmt = myConn->createStatement(); // creating id column, creates an error
myRes = myStmt->executeQuery("ALTER TABLE password_table ADD id INT(200) NOT NULL AUTO_INCREMENT FIRST, ADD PRIMARY KEY(id);");
return 0;
}
It should be noted that, if I do the same command in mysql itself, it will work, but not in code.
First, I thought that it's because of quotation marks, but that it did not work. Than I tried to reinstall mysql connector, but it did not work either.

Answer 1

The issue is that you are calling:
myRes = myStmt->executeQuery("ALTER TABLE password_table DROP id;");
for a query that doesn't produce results.
Instead, call
myStmt->execute("ALTER TABLE password_table DROP id;");
which returns bool to check if the command has results.
PS: and don't forget to add a try catch block on this code otherwise your program will crash and you never know why something is failing.