How to Assign Hex value to Field

ts7300 · 09-30-2009, 05:03 AM

Hi,
Below are the Table and I want to assign hex value to field hotter_alert i.e.0xFE.Below I am trying to Modify field attributes.
----------------------------------------------------------
mysql> ALTER TABLE location MODIFY hotter_alert hex();
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'hex()' at line 1
I do not Know whether it's right or wrong.Please let me know how can I give Hex to field Hotter_alert.
+----------------------+---------------+------+-----+------------+----------------+
| Field | Type | Null | Key | Default Extra |
+----------------------+---------------+------+-----+------------+----------------+
| id | int(10) | NO | PRI | NULL | auto_increment |
| name | varchar(40) | NO | | | |
| lat | decimal(10,4) | NO | | 0.0000 | |
| lng | decimal(10,4) | NO | | 0.0000 | | |
| hotter_alert | int(10) | YES | | NULL | |
| inserted | date | NO | | 0000-00-00 | |
| updated | date | NO | | 0000-00-00 | |
+----------------------+---------------+------+-----+------------+-------------

diilbert · 09-30-2009, 05:35 AM

Using the column type of integer and inserting something link: insert into test (test) values (0x0a) will work. If you are using phpMyAdmin to insert the data you will need to use straight SQL since the builtin insert function will try inserting the data as text and parse it out.

Reference: http://dev.mysql.com/doc/refman/5.0/...al-values.html

ts7300 · 09-30-2009, 06:14 AM

ts7300 · 10-03-2009, 02:10 AM

Hi,
I am not big champ. of C.Next thing I am trying to do using these value 0xFE and 0x02 to control the I/O of board using MYSQL C based API at baord side.And using PHP admin to insert the value in MYSQL Database.And hotter_alert | varchar(40) | YES | | NULL | | hotter_alert is the field name and want to control the I/O of board from server side by inserting value.From BOARD side I am able tho fetch hooter_alert field value as row[0] and *PCDR is pointer to which want to assign row[0] value.Problem I am getting is that I am able to fetch the value from Database but Not able to assign properly this value *PCDR register.What I thought Problem is that row[0] value fetching from DATABASE come in string of character as such it's printing right value only when %s is given.And *PCDR is declared as unsigned int.Please suggest me How can I assign row[0] value to *PCDR register,so that I can control I/O from server side.

Code:

#include <stdio.h>
#include <stdlib.h>
#include "mysql.h"
#include<unistd.h>
#include<sys/types.h>
#include<sys/mman.h>
#include<stdio.h>
#include<fcntl.h>
#include<string.h>

void exiterr(int exitcode)
{
    fprintf( stderr, "%s\n", mysql_error(conn) );
    exit( exitcode );
}
int main(int argc, char **argv)
{
   MYSQL *conn;
   MYSQL_RES *res;
   MYSQL_ROW row;
    uint i = 0;
  char *server = "10.64.21.63";
   char *user = "root";
   char *password = "PASSWORD"; /* set me first */
   char *database = "mysql";
 unsigned char *start;
   volatile unsigned int *PCDR, *PCDDR;
   int fd = open("/dev/mem", O_RDWR);
start = mmap(0, getpagesize(), PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0x80840000);
   PCDR = (unsigned int *)(start + 0x08);     // port c data register
   PCDDR = (unsigned int *)(start + 0x18);    // port c direction register

   (!mysql_real_connect(conn, server,
         user, password, database, 0, NULL, 0)) 
        exiterr(1);

    if (mysql_select_db(conn,"location"))
        exiterr(2);

    if (mysql_query(conn,"SELECT hotter_alert from location"))
        exiterr(3);

    if (!(res = mysql_store_result(&mysql)))
        exiterr(4);

    while((row = mysql_fetch_row(res))) {
        for (i=0 ; i < mysql_num_fields(res); i++) 
char * val=row[0]
*PCDDR = 0x01; // Make bit 0 an output Port C bit 0 is connected to the FET
*PCDR = val; // Turn the FET on
 printf("%s\n",row[0]);
    }

    if (!mysql_eof(res))
        exiterr(5);

    mysql_free_result(res);
    mysql_close(&mysql);
   close(fd);
   return 0;
}