Easy MYSQL C API interface

mysql_api.c

#ifndef MYSQL_API_H
#define MYSQL_API_H

#include <mysql.h>
#include <stdio.h>

typedef struct MYSQL_CTX {
	/* public */
	unsigned int rows;
	unsigned int columns;
	
	/* private */
	MYSQL *_conn;
	MYSQL_RES *_res;
	
	struct {
		char *host;
		char *user;
		char *pass;
		char *db;
		int port;
	} login;
	
} MYSQL_CTX;

MYSQL_CTX *MYSQL_begin(char *host, int port, char *user, char *pass, char *db);
MYSQL_ROW MYSQL_query(MYSQL_CTX *ctx, char *query);
MYSQL_ROW MYSQL_offset(MYSQL_CTX *ctx, unsigned int index);
void MYSQL_end(MYSQL_CTX *ctx);

static void MYSQL_error(MYSQL_CTX *ctx) {
	MYSQL *conn;
	char error_str[512];
	unsigned int error_number = mysql_errno(ctx->_conn);
	
	if (error_number == 0) return;
	
	conn = ctx->_conn;
	ctx->_conn = NULL;
	
	if (error_number == 2003) return; //dont log cant connect
	if (error_number == 1053) return; //dont log shutdown in progress
	
	snprintf(error_str, sizeof(error_str)-1, "MYSQL ERROR %i: %s", error_number, mysql_error(conn));
	
	MessageBox(NULL, error_str, "MYSQL ERROR!", MB_ICONERROR);
}

MYSQL_CTX *MYSQL_begin(char *host, int port, char *user, char *pass, char *db) {
	MYSQL_CTX *ctx;
	
	if ((ctx = malloc(sizeof(MYSQL_CTX))) == NULL) return NULL;
	
	memset(ctx, 0, sizeof(MYSQL_CTX));
	
	ctx->login.host = host;
	ctx->login.port = port;
	ctx->login.user = user;
	ctx->login.pass = pass;
	ctx->login.db 	= db;
	
	return ctx;
}

void MYSQL_end(MYSQL_CTX *ctx) {
	
	if (ctx == NULL) return;
	
	if (ctx->_res) mysql_free_result(ctx->_res);
	
	if (ctx->_conn) mysql_close(ctx->_conn);
	
	memset(ctx, 0, sizeof(MYSQL_CTX));
	
	free(ctx);
}

MYSQL_ROW MYSQL_query(MYSQL_CTX *ctx, char *query) {
	MYSQL_ROW row;
	
	if (ctx == NULL) return NULL;
	
	while (ctx->_conn == NULL) {
		
		if ((ctx->_conn = mysql_init(NULL)) == NULL) return NULL;
		
		if (!mysql_real_connect(ctx->_conn, 		ctx->login.host,
								ctx->login.user, 	ctx->login.pass,
								ctx->login.db, 		ctx->login.port, NULL, 0))
			MYSQL_error(ctx);
	}
	
	if (mysql_query(ctx->_conn, query)) {
		MYSQL_error(ctx);
		return NULL;
	}
	
	if (ctx->_res) {
		mysql_free_result(ctx->_res);
		ctx->rows = 0;
		ctx->columns = 0;
	}
	
	if ((ctx->_res = mysql_store_result(ctx->_conn)) == NULL) {
		MYSQL_error(ctx);
		return NULL;
	}
	
	if ((row = mysql_fetch_row(ctx->_res)) == NULL) {
		MYSQL_error(ctx);
		return NULL;
	}
	
	ctx->rows = mysql_num_rows(ctx->_res);
	ctx->columns = mysql_num_fields(ctx->_res);
	
	return row;
}

MYSQL_ROW MYSQL_offset(MYSQL_CTX *ctx, unsigned int index) {
	MYSQL_ROW row;
	
	if (ctx == NULL) return NULL;
	
	if (ctx->_res == NULL) return NULL;
	
	if (index >= ctx->rows) return NULL;
	
	mysql_data_seek(ctx->_res, index);
	
	if ((row = mysql_fetch_row(ctx->_res)) == NULL) return NULL;
	
	return row;
}

#endif /* MYSQL_API_H */

/*///////////////////////////////////
	
		Testing:
		
///////////////////////////////////*/

int main(void) {
	MYSQL_CTX *ctx;
	MYSQL_ROW row;
	int i;
	
	ctx = MYSQL_begin("localhost", 3306, "root", "password", "database");
	{
		row = MYSQL_query(ctx, "SELECT * FROM Table;");
		
		if (row == NULL) return 1;
		
		for (i=0; i<ctx->columns; i++)
			printf("%s\t", row[i]);
	}
	MYSQL_end(ctx);
	
	return 0;
}