Apples and Oranges, Part II: A Linux DBMS Comparison - page 8

The Database Design

The differences between mSQL's and MySQL's C API are very, very small. Thus, there is even an automatic converter. The principal differences are:

• mSQL does not store a connection data block, only a number (int bookstore)
• some mSQL functions don't take the connection as an argument
• mSQL function names are Pascalish (they use StudlyCaps instead of underscores)

The handy MONEY data type is a fixed-precision decimal fraction type with two decimals. To make mSQL correctly store integer numbers of cents in MONEY columns, I needed to convert them, casting them into floats, dividing them and formatting them in the sprintf statement of the add_new_book() function.

This is list_books(), ported to mSQL:

void
list_books(void)
{
  int count;
  m_result *result;

  msqlQuery(bookstore, "SELECT ARTICLE_NO, AUTHOR_FIRST_NAMES,\
AUTHOR_LAST_NAMES, TITLE, ISBN, WHOLESALE_PRICE, RETAIL_PRICE,\
COPIES_AVAILABLE FROM BOOK");
  result = msqlStoreResult();

  for(count = msqlNumRows(result); count > 0; count--)
	{
	  m_row record;
	  record = msqlFetchRow(result);

	  printf("\nArticle no. %s\n", record[0]);
	  printf("%s, %s:\n", record[2], record[1]);
	  printf("    %s (%s)\n", record[3], record[4]);
	  printf("Bought at %s; selling at %s; %s copies available\n\n",
			 record[5], record[6], record[7]);
	};

  msqlFreeResult(result);
}

Documentation for mSQL's C API can be found in the mSQL manual that ships with mSQL as PostScript and as a large HTML file.