Im trying to call my str date variable in this function:
int main(int argc, char **argv)
{
int status = 0;
char query[300], data[15], hora[10];
strDataHora(data, hora);
printf("Date: %s\n", data);
MYSQL *con = mysql_init(NULL);
if (con == NULL)
{
fprintf(stderr, "mysql_init() failed\n");
exit(1);
}
if (mysql_real_connect(con, "localhost", "root", "ufmg3duc",
"stream_net", 0, NULL, CLIENT_MULTI_STATEMENTS) == NULL)
{
finish_with_error(con);
}
if (mysql_query(con, "SELECT Id FROM audiencia WHERE data LIKE ('%s') AND (hora LIKE ('%:00:%') OR hora LIKE ('%:30:%')) AND hora > '03:01'",data))
{
finish_with_error(con);
}
But I dont know how to call 'date' in mysql_query:
if (mysql_query(con, "SELECT Id FROM audiencia WHERE data LIKE ('%s') AND (hora LIKE ('%:00:%') OR hora LIKE ('%:30:%')) AND hora > '03:01'",data))
How can i select Id when my actual date is a str variable type?
You have to store this query in a variable (eg. with sprintf or snprintf) and escape all those %using %%
char query[300];
...
sprintf(query, "SELECT Id FROM audiencia WHERE data LIKE ('%s') ...", data);
mysql_query(con, query);
Related
I need an advice from community. I need to store somewhere data from mysql so later I could compare data. I tried to put everything to struct, but I realized that struct was gone after loop, and that i cannot create that struct name would be variable. Like this:
struct Columns (variable);
So basically I need to store columns information like field, type, key etc.. I don't know how much there will be tables.
My struct:
struct Columns {
char field[1000];
char type[50];
char null[10];
char key[20];
char defaul[50];
char extra[50];
};
Code part:
if (mysql_query(conn, "Show tables;")){
fprintf(stderr, "%s\n", mysql_error(conn));
exit(1);
}
res = mysql_store_result(conn);
printf("MySQL Tables in mysql database:\n");
while ((row = mysql_fetch_row(res)) != NULL){
printf("%s\n", row[0]);
sprintf(str, "Show columns from %s;", row[0]); //row[0]-is table names
sprintf(str1, "lentele_%s", row[0]);
printf("%s\n", str1);
struct Columns str1;
if (mysql_query(conn, str)){
fprintf(stderr, "%s\n", mysql_error(conn));
exit(1);
}
res2 = mysql_use_result(conn);
while ((row2 = mysql_fetch_row(res2)) != NULL){
strcpy(str1.field, row2[0]);
printf("Belekas Column field %s\n", str1.field);
}
There are 6 columns on each table: field || type || null || key || default || extra
As I said, i will need that data for later comparison.
i met a issue during my development on mysql and linux C.
as the procedure use temporary params, so I think it will not affect following sql query. but my test is failed and report errno:2014.
the procedure I used is :
delimiter //
drop procedure if exists pbx_r_eid_svcid;
CREATE PROCEDURE `pbx_r_eid_svcid`(IN input_eid varchar(16))
begin
declare exe_result int default -1;
declare out_svcip varchar(64) default "";
declare out_svcport varchar(64) default "";
select exe_result,out_svcip,out_svcport;
end;//
delimiter;
C code:
#include <mysql/mysql.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
int main(int argc, char *argv[])
{
MYSQL *mysql;
int timeout=atoi(argv[1]);
char escape[64] = "";
char orig[64] = "";
char buf[128] = "";
int rc = 0;
MYSQL_RES *res;
mysql = mysql_init(NULL);
mysql_options(mysql, MYSQL_OPT_READ_TIMEOUT, &timeout);
mysql_options(mysql, MYSQL_OPT_WRITE_TIMEOUT, &timeout);
mysql_real_connect(mysql, "127.0.0.1", "root", "123456", "center_distribute", 3306,"/var/run/mysqld/mysqld.sock", CLIENT_FOUND_ROWS | CLIENT_MULTI_STATEMENTS);
snprintf(buf,128, "call pbx_r_eid_svcid('00000002')", "11");
if (mysql_real_query(mysql,buf,strlen(buf)))
{
int err_no = mysql_errno(mysql);
fprintf(stderr, "Failed to insert row, Error: %d %s\n", err_no,
mysql_error(mysql));
}
res = mysql_store_result(mysql);
if(0 == mysql_affected_rows(mysql) || res == NULL)
{
rc = 6;
goto end;
}
mysql_free_result(res);
snprintf(buf,128,"select * from enterprise_info;");
/******************************/
/*wrong query return out of sync*/
if (mysql_real_query(mysql,buf,strlen(buf)))
{
int err_no = mysql_errno(mysql);
fprintf(stderr, "Failed to insert row, Error: %d %s\n", err_no,
mysql_error(mysql));
}
res = mysql_store_result(mysql);
if(0 == mysql_affected_rows(mysql) || res == NULL)
{
rc = 7;
goto end;
}
mysql_free_result(res);
end:
printf("%d\n",rc);
mysql_close(mysql);
return 0;
}
second mysql select will repsonse out of sync error
test reult:
./mt 5
Failed to insert row, Error: 2014 Commands out of sync; you can't run this
command now
7
any comment should be helpful.
Thanks.
I have a temperature sensor hooked up to a Raspberry Pi, I am able to read and printf the temperature. What I am trying to do next is to get the values from the sensor and have them get logged into a MySQL database.
Everything works, except, I can not figure out how to format the MySQL insert Query to use the f variable and the h variable that is generated by the read_dht_data() function and pass it to the MIA_temp_insert(float f, float h).
#include <stdio.h>
#include <stdlib.h>
#include <mysql/mysql.h>
#include <wiringPi.h>
#include <stdint.h>
#define MAX_TIMINGS 85
#define DHT_PIN 3 /* GPIO-22 */
int data[5] = { 0, 0, 0, 0, 0 };
float temp_f;
static char *host = "XXX.XXX.XXX.XXX";
static char *user = "XXX";
static char *password = "XXX";
static char *dbname = "XXX";
unsigned int port = 3306;
static char *unix_socket = NULL;
unsigned int flag = 0;
static MYSQL *conn; //Needed to be static so all of the functions can draw from it
void MIA_mysql_connection()
{
// Connecting to the Database
conn = mysql_init(NULL);
if (!(mysql_real_connect(conn, host, user, password, dbname, port, unix_socket, flag)))
{
fprintf(stderr, "\n Error: %s [%d] \n", mysql_error(conn),mysql_errno(conn));
exit (1);
}
//Connected
printf ("We Are Connected \n");
}
void MIA_mysql_close()
{
//Closing Connection
mysql_close(conn);
}
void MIA_temp_insert(float f, float h)
{
//Inserting into MySQL Table
if(mysql_query(conn, "INSERT INTO `temperature` (`id`, `Date`,`Time`, `Temperature`, `Humidity`) VALUES (NULL, CURRENT_DATE(), CURRENT_TIME(), '%f' , '%f')") !=0)
{
fprintf(stderr, "%s\n", mysql_error(conn));
exit (-1);
} else {
printf("Rows were insert \n");
}
}
void read_dht_data()
{
uint8_t laststate = HIGH;
uint8_t counter = 0;
uint8_t j = 0, i;
data[0] = data[1] = data[2] = data[3] = data[4] = 0;
/* pull pin down for 18 milliseconds */
pinMode( DHT_PIN, OUTPUT );
digitalWrite( DHT_PIN, LOW );
delay( 18 );
/* prepare to read the pin */
pinMode( DHT_PIN, INPUT );
/* detect change and read data */
for ( i = 0; i < MAX_TIMINGS; i++ )
{
counter = 0;
while ( digitalRead( DHT_PIN ) == laststate )
{
counter++;
delayMicroseconds( 1 );
if ( counter == 255 )
{
break;
}
}
laststate = digitalRead( DHT_PIN );
if ( counter == 255 )
break;
/* ignore first 3 transitions */
if ( (i >= 4) && (i % 2 == 0) )
{
/* shove each bit into the storage bytes */
data[j / 8] <<= 1;
if ( counter > 16 )
data[j / 8] |= 1;
j++;
}
}
/*
* check we read 40 bits (8bit x 5 ) + verify checksum in the last byte
* print it out if data is good
*/
if ( (j >= 40) &&
(data[4] == ( (data[0] + data[1] + data[2] + data[3]) & 0xFF) ) )
{
float h = (float)((data[0] << 8) + data[1]) / 10;
if ( h > 100 )
{
h = data[0]; // for DHT11
}
float c = (float)(((data[2] & 0x7F) << 8) + data[3]) / 10;
if ( c > 125 )
{
c = data[2]; // for DHT11
}
if ( data[2] & 0x80 )
{
c = -c;
}
float f = c * 1.8f + 32;
//printf( "Humidity = %.1f %% Temperature = %.1f *C (%.1f *F)\n", h, c, f );
printf ("Temp of the room is : %.1f \n",f);
//Insert Data into MIA Temperature Table
MIA_temp_insert(10.0,11.1);
}else {
//printf( "Data not good, skip\n" );
}
}
int main ()
{
printf( "Raspberry Pi DHT11/DHT22 temperature/humidity test\n" );
if ( wiringPiSetup() == -1 )
exit( 1 );
while ( 1 )
{
MIA_mysql_connection();
read_dht_data();
delay (1000);
MIA_mysql_close();
printf("End of program \n");
}
return(0);
}
You cannot use printf()-style format specifiers in mysql_query() directly as you have above. Instead, you can use sprintf() or snprintf() to write the format string -- with the formatted numbers instead of format specifiers -- into a buffer... then pass that as your query string.
So in MIA_temp_insert(), instead of the following:
if(mysql_query(conn, "INSERT INTO `temperature` (`id`, `Date`,`Time`, `Temperature`, `Humidity`) VALUES (NULL, CURRENT_DATE(), CURRENT_TIME(), '%f' , '%f')") !=0)
{
fprintf(stderr, "%s\n", mysql_error(conn));
exit (-1);
/* ...etc... */
...you could try this:
/* Your original query string, with the %f specifiers */
const char *formatstring = "INSERT INTO `temperature` (`id`, `Date`,`Time`, `Temperature`, `Humidity`) VALUES (NULL, CURRENT_DATE(), CURRENT_TIME(), '%f' , '%f')";
/* snprintf() the query into a buffer, to fill in the numbers */
char buf[256]; // should be large enough for the query with the numbers filled in
if (snprintf(buf, sizeof(buf), formatstring, f, h) >= sizeof(buf))
{
exit(-1); // if snprintf() returned sizeof(buf) or more, buf was too short
}
/* call mysql_query() with the formatted query from the buffer */
if (mysql_query(conn, buf) != 0)
{
fprintf(stderr, "%s\n", mysql_error(conn));
exit (-1);
/* ...etc... */
I'm new to mysql programming on c. I need to check if a certain user exists in a table. How can I do this using the C API?
Here's what I've got, but it isn't working:
if (mysql_query(con, "SELECT * FROM Users WHERE UserName='user3'"))
{
finish_with_error(con);
}
MYSQL_RES *result = mysql_store_result(con);
if (result == NULL)
{
finish_with_error(con);
}
int count = mysql_field_count(con);
printf("%d\n", count );
For anyone interested, this is something I wrote using the comments, and finally ended up using.
if (mysql_query(con, "SELECT field FROM table WHERE userName='user1'"))
{
finish_with_error(con);
}
MYSQL_RES *result = mysql_store_result(con);
if (result == NULL)
{
finish_with_error(con);
}
MYSQL_ROW row;
MYSQL_FIELD *field;
if (row = mysql_fetch_row(result))
{
printf("%s\n", row[0]);
db_pwd = row[0];
}
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.
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 :)