Question

I can use mysql from terminal to query data and I try to connect to mysql server with C but here is some problem i don’t know to fix but seems like version conflict.

#include <my_global.h>
#include <mysql.h>

int main(int argc, char **argv)
{
  MYSQL *conn;
  conn = mysql_init(NULL);
  if (conn == NULL) {
      printf("Error %u: %s\n", mysql_errno(conn), mysql_error(conn));
      exit(1);
}

// upper code works

// following don't work...
if (mysql_real_connect(conn, "localhost", "username", "password", NULL, 0, NULL, 0) == NULL)
{
  printf("Error %u: %s\n", mysql_errno(conn), mysql_error(conn));
  exit(1);
}
etc...

When I start this code message “Error 2002: Can’t connect to local MySQL server through socket ‘/tmp/mysql.sock’ (2)” appears.
Problem is that I don’t have mysql.sock anywhere in computer but have /var/run/mysqld/mysqld.sock.
In linker options I added /var/lib/libmysql.so and program compiles OK.

Is here any simple way to get this to work?

Answer 1

why not connecting directly to the socket?

mysql_real_connect(conn, "localhost", "username", "password",
                   NULL, 0, "/var/run/mysqld/mysqld.sock", 0)

I have no environment to test it right now, but I think it should work

To answer question in your comment:

I think its’ because of your configuration, mysql’s default configuration is to store socket at /tmp/mysql.sock, and it didn’t find it there, you just specified your location of the socket, this is not a portable solution, it depends on purpose of your application