/*
* gcc example.c -o example  `mysql_config --cflags --libs`
*/
#include <mysql.h>
#include <stdio.h>
#include <string.h>

void run_single_test(MYSQL *conn) {

  if (mysql_query(conn, "update t1 set a = 1 where b = 1")) {
    printf("ERROR: %s\n", mysql_error(conn));
  } else {
    printf("SUCCESS: %s\n", mysql_error(conn));
  }

}

void run_multi_test(MYSQL *conn) {

  if (mysql_query(conn, "update t1 set a = 1 where b = 1;update t1 set a = 2 where b = 2;update t1 set a = 3 where b = 3;")) {
    printf("ERROR: %s\n", mysql_error(conn));
  } else {
    printf("SUCCESS: %s\n", mysql_error(conn));
  }

}

int main(int argc, char **argv) {

  MYSQL *conn = mysql_init(NULL);

  if (conn == NULL)  {
      fprintf(stderr, "%s\n", mysql_error(conn));
      exit(1);
  }

  if (mysql_real_connect(conn, "127.0.0.1", "root", "", "test", 4000, NULL, 0) == NULL) {
//   if (mysql_real_connect(conn, "127.0.0.1", "msandbox", "msandbox", "test", 8021, NULL, 0) == NULL) {
      fprintf(stderr, "%s\n", mysql_error(conn));
      mysql_close(conn);
      exit(1);
  }

  run_single_test(conn); // works
  run_multi_test(conn); // fails
  mysql_set_server_option(conn, MYSQL_OPTION_MULTI_STATEMENTS_ON);
  run_single_test(conn); // works
  run_multi_test(conn); // works

  mysql_close(conn);
  exit(0);

}

nullnotnil@ubuntu:~$ gcc example.c -o example  `mysql_config --cflags --libs` && ./example 
ERROR: Table 'test.t1' doesn't exist
ERROR: client has multi-statement capability disabled
ERROR: Table 'test.t1' doesn't exist
ERROR: Table 'test.t1' doesn't exist