:Connect C applications to OceanBase Database

Sample code

The following sample code shows how to connect a C application to OceanBase Database:

mysql_library_init(0, NULL, NULL);
MYSQL *mysql = mysql_init(NULL);

/* Use the CLIENT_MULTI_STATEMENTS option to connect to the server. */
if (mysql_real_connect (mysql, host_name, user_name, password,
    db_name, port_num, socket_name, CLIENT_MULTI_STATEMENTS) == NULL)
{
  printf("mysql_real_connect() failed\n");
  mysql_close(mysql);
  mysql_library_end();
  exit(1);
}

/* Execute multiple statements. */
status = mysql_query(mysql,
                     "DROP TABLE IF EXISTS tbl1;\
                      CREATE TABLE tbl1(id INT);\
                      INSERT INTO tbl1 VALUES(110);\
                      UPDATE tbl1 SET id=120 WHERE id=110;\
                      SELECT * FROM tbl1;\
                      DROP TABLE tbl1");
if (status)
{
  printf("Could not execute statement(s)");
  mysql_close(mysql);
  mysql_library_end();
  exit(0);
}

/* Process the result of each statement. */
do {
  /* Check whether the current statement returns data. */
  result = mysql_store_result(mysql);
  if (result)
  {
    /* If yes, process the rows and release the result set. */
    process_result_set(mysql, result);
    mysql_free_result(result);
  }
  else          /* No result set generated or an error occurred. */
  {
    if (mysql_field_count(mysql) == 0)
    {
      printf("%lld rows affected\n",
            mysql_affected_rows(mysql));
    }
    else  /* An error occurred. */
    {
      printf("Could not retrieve result set\n");
      break;
    }
  }
  /* Check whether more results are generated.  The value -1 indicates no. The value 0 indicates yes, which means the loop continues. A value greater than 0 indicates that an error occurred. */
  if ((status = mysql_next_result(mysql)) > 0)
    printf("Could not execute statement\n");
} while (status == 0);

mysql_close(mysql);
mysql_library_end();