MySQL Header

[elvenspike]

I threw together a useful little header that's intended to make MySQL quick and easy to manage from within a C++ application. Just wanted to post it here and get some opinions on it...

// EsKueEl.h

#include <iostream> // input/output stream
#include <mysql.h> // so the ksql class can use mysql o.o
#include <string> // so we can use strings
using namespace std; // the standard namespace o.o

class qksql { // QKSQL : Quick MySQL
	public: // the public functions and variables
		void connect(char host[1000], char usr[1000], char pass[1000], char db[1000]); // the connect function...
		void disconnect(); // time to go bye bye!
		int query(char myquery[10000]); // query my query pl0x
		char query_result(); // a char-returning function... O.o
		int query_state; // the query_state o.o yeah, its public.
		MYSQL *connection, mysql; // mysql stuff...
		MYSQL_RES *result; // mysql stuff....
		MYSQL_ROW row; // mysql stuff...
		void max_res(int x); // use this function to set the max results, this is good for a simple querying program
	private: // getting to the private variables!
		int i; // the count up int :O
		int t; // the function'd row
}; // the end... :O

void qksql::connect(char host[1000], char usr[1000], char pass[1000], char db[1000]) { // connection with defined variables
	mysql_init(&mysql); // initiating mysql :O
	//connection = mysql_real_connect(&mysql,"host","user","password","database",0,0,0);
	connection = mysql_real_connect(&mysql,host,usr,pass,db,0,0,0);
	if (connection == NULL) { // if the connection fails
		cout << mysql_error(&mysql) << endl; // give us an error
	}
}

void qksql::disconnect() { // disconnectz0r
	mysql_free_result(result); // freeing query results
	mysql_close(connection); // dropping the connection
}

int qksql::query(char myquery[10000]) { // query teh stringz
	query_state = mysql_query(connection, myquery); // querying!
	if (query_state != 0) { // if the query state has an error...
		cout << mysql_error(connection) << endl; // show us what happened.
		return 1; // returning with error code 1 :O
	}
}

char qksql::query_result() {
	result = mysql_store_result(connection); // results!
	while ( ( row = mysql_fetch_row(result)) != NULL ) { // OMG! lets see if the results are working
		fast: // heh... yes, ik, ik... goto is very bad...
		if (i < t) { // if i < t
			cout << row[i] << endl;; // output row[i]
			++i; // add 1 to i
			goto fast; // go to fast :O
		} // O.o why was this a char again?
	} // seriously, it has no return value
} // whatever... i forget :D

void qksql::max_res(int x) { // the max res function
	t = x; // private T is now equal to incoming X
} // bye bye! 

NOTE :

Compiling with a UNIX command line compiler? Include the code below at the end of your compiler command.

COMMAND :

-L/usr/include/mysql -lmysqlclient -I/usr/include/mysql

EXAMPLE (g++) :

g++ file.cpp -L/usr/include/mysql -lmysqlclient -I/usr/include/mysql

[guestgulkan]

Two things to start off with:
1. This isn't really a header is it?
2. Why are you using char arrays?

[elvenspike]

1) i used it as one and it worked fine. Is there really a qualification for what a header does? it just saves you time so you don't have to type all of this out. its as simple as

qksql [variablename];

and you can use functions.
2) Because that's how you put input into all of these o.o, what else would you use? strings don't work with them.

[Incubbus]

are you aware of all the capabilities strings offer to you?...

[helios]

If myquery was an std::string, you could do mysql_query(connection, myquery.c_str()).

[elvenspike]

hmm, thanks helios, that solved should solve some of the problems i was having with it.
@Incubbus,
you are aware that a char array is essentially a string, right?
also, i just wanted a change of pace, i ALWAYS use strings.

[helios]

Incubbus was talking about std::strings, or any other kind of string object, not null-terminated char arrays.

Unless you're doing some sort of high speed string processing (and when I say high speed, I mean high speed) it's not worth to risk having all the potential problems std::strings prevent.

[guestgulkan]

With regard to the Is it or is it not a header thing - I was trying to point out
that if you #include "EsKueEl.h" in more than one file - you will end up with
the linker giving redefinition errors.

[Incubbus]

even if myquery is not an null-terminated string you could do this by using string::data() its the string::c_str() without the NULL-character at the end...

so you could use it for the mysql_query and for real connect etc...

i never ment to offend you - if it did sound like...


and as guestgulkan said... dont forget the include warden/guard

[chrisname]

To avoid the issue guestgulkan pointed out...

#ifndef _MY_HEADER_H_
#define _MY_HEADER_H_

myCode;

#endif // _MY_HEADER_H_ not defined

... should work.

[elvenspike]

alright, thanks chris, i'll add that to the one i've got saved. although i have yet to add the changes everyone's mentioned, i didn' have internet for most of today, and the thing helios mentioned originally i didn't add yet. i guess i'll add it now or in a bit. thanks though.

{EDIT} Just incorperated the changes into my file. Anything else? (if that's it, i might as well replace the goto with a for statement :O)