How to separate result values in different rows using Mysql query - mysql

Question

I created this table (results) in my sql database (test)
CREATE DATABASE `test`;
USE `test`;
CREATE TABLE `results` (
`number` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
`id_machine` int(10) unsigned NOT NULL,
`value` float NOT NULL,
`datetime` datetime NOT NULL,
PRIMARY KEY (`number`),
UNIQUE KEY `indice_UNIQUE` (`number`)
) ENGINE=InnoDB AUTO_INCREMENT=100;
My external device gives me these results:
+DATA: 43 BYTES FROM 0000:0000 (045)
Machine_8: (T=22.22, HR=42.56, Dw=8.95, VCC=3.64V)
and with the usage of strtok I get some values of these results to save them in the database:
Results: 8, 22.22, 42.56, 8.95, 3.64
I would like to save my data in my table in this way:
101, 8, 22.22, 2013-06-05 14:03:00
102, 8, 42.56, 2013-06-05 14:03:00
103, 8, 8.95, 2013-06-05 14:03:00
104, 8, 3.64, 2013-06-05 14:03:00
This is my code in my function until now
int learn_port2(int fd)
{
MYSQL *conn;
MYSQL_RES *res;
MYSQL_RES *res1;
MYSQL_ROW row;
char *server = "127.0.0.1";
char *user = "root";
char *password = "***"; // got tot keep my data secret
char *database = "test";
conn = mysql_init(NULL);
if(!mysql_real_connect(conn, server, user, password, database, 0, NULL, 0))
{
fprintf(stderr, "%s\n", mysql_error(conn));
return -1;
//finish_with_error(conn);
}
int n, i;
char buff[300];
memset(buff, 0, sizeof(buff));
for (int x = 0; x<1; x++)
//for (;;)
{
char id_machine[35] = "";
char temp[35] = "";
char hum[35] = "";
char dw[35] = "";
char vol[45] = "";
char* ptr;
int i,nodo,nodo1;
float temp, hum, dw, vcc;
n=read(fd,buff,sizeof(buff));
sleep(1);
printf("%s", buff);
printf("\n");
if (buff[37] == 'N' || buff[38] == 'N' || buff[39] == 'N' || buff[40] == 'N' )
{
ptr = strtok(buff, "Machine_,=T:HR:DW:Vcc()");
i = 0;
while (ptr != NULL)
{
if (i == 9)
strcat(id_machine, ptr); // copies Nodo
if (i == 10)
strcat(temp, ptr); // copies T
if (i == 11)
strcat(hum, ptr); // copies HR
if (i == 13)
strcat(dw, ptr); // copies DW
if (i == 15)
strcat(vol, ptr); // copies Vcc
ptr = strtok(NULL, "Machine_,=T:HR:DW:Vcc()");
i++;
}
printf("Results: %s, %s, %s, %s, %s\n", id_machine, temp, hum, dw, vol);
}
char query[]="INSERT INTO results(`id_machine`,`value`,`valor`) VALUES(id_machine,'14',value)";
if(mysql_query(conn, query))
{
fprintf(stderr, "%s\n", mysql_error(conn));
return -1;
}
res = mysql_use_result(conn);
}
}
How can I modify the char query[] to have the results which I want? Or if there are some examples like this.

Answer 1

To make a parameterized query you could use something like the following...
The example uses vsnprintf() to take a printf like format string and a variable number of arguments after it to print the query into a temporary buffer and then pass the buffer to the MYSQL query. In this way you can get a paramaterized query...
vsnprintf() accepts a variable parameter list, va_list and also is buffer-overflow safe.
#include <stdio.h>
#include <stdarg.h>
#include <string.h>
#define BUFSTRLEN 255
/* Returns -1 if the internal buffer was not large enough to hold the formatted
* string, or a format error occurred. If neither condition occurred then the
* result of the MYSQL query is returned... */
int DoMysqlQuery(MYSQL *conn, char const *printfstring, ...)
{
int len;
va_list args;
char buffer[BUFSTRLEN + 1];
memset(buffer, '\0', sizeof(buffer));
va_start(args, printfstring);
len = vsnprintf(buffer, BUFSTRLEN, printfstring, args);
va_end(args);
/* Did the buffer print work ? */
if( len < 0 || len >= BUFSTRLEN + 1 )
return -1;
return mysql_query(conn, buffer);
}
int main(int argc, char const *argv[])
{
int result;
MYSQL mysqlConn = ...;
/* Example stuff to send to the function.... */
char *id_machine= "8";
char *value= "1234";
char *valor= "1";
/* Send the query */
result = DoMysqlQuery(
&mysqlConn,
"INSERT INTO results(`id_machine`,`value`,`valor`) VALUES(%s,'%s',%s);",
id_machine, value, valor);
if( result )
{
/* handle error etc... *.
}
}
In this example, the query string that will be sent to mysql_query() is:
INSERT INTO results(id_machine,value,valor) VALUES(8,'1234',1);
Hope this helps :)