Novice needs help with interface

Hello,

I'm a novice trying to understand how to create an interface and I'm having trouble with structures and pointers to structures.
I have no experience with C/C++ so that could be why I'm struggling.

I couldn't find a tutorial so I have been looking at mysql.bac and the MySQL C api reference here: dev.mysql.com/doc/refman/5.0/en/c-api-functions.html and trying to figure it out what to do from those but I'm afraid I need someone to help me understand.

At first glance I thought all I had to do was pass a long wherever a pointer was required and that made sense to me because I thought the long would contain the memory address of whatever was being pointed to but then I noticed this:

IMPORT "mysql_fetch_row(long)" FROM mysql_LIB$ TYPE long*
where the C function is defined as:
MYSQL_ROW mysql_fetch_row(MYSQL_RES *result)

and then this:
IMPORT "mysql_fetch_fields(long)" FROM mysql_LIB$ TYPE long*
this function in the MySql reference is defined like as:
MYSQL_FIELD *mysql_fetch_fields(MYSQL_RES *result)


If my limited understanding of C is correct doesn't the definition
MYSQL_ROW mysql_fetch_row(MYSQL_RES *result)
return a structure

and

MYSQL_FIELD *mysql_fetch_fields(MYSQL_RES *result)
return a pointer to a structure?

And if I'm right about that how come the return value in BaCon is defined the same way for both functions, i.e. long*?

Also would Uint32 be declared as int or long?

Thanks to anybody who can bring clarity to my cloudy brain.