How do you save a MySQL query result into a variable in c

Question

I have the below MySQL query which when done in the MySQL console shows the correct result. I can't figure out how to store the result into a variable in my c program however.

Here is the code that I type into the MySQL interface:

mysql> SELECT id FROM Stations where name = 'AE0';

This is what it returns:

+----+
| id |
+----+
|  1 |
+----+

I need the above value of '1' stored into a variable in my c program. The MySQL query is called from my c program using this code:

MYSQL_RES *result;
MYSQL_ROW row;
length=sprintf(query,"SELECT id FROM Stations where name ='AE0'");
myquery(conn,query,length);
result=mysql_store_result(conn);
row=mysql_fetch_row(result);

I'm unsure if the value I'm looking for is stored in 'result', whether it is or isn't, how can I find it and save it into an integer?

Answer 1

short answer:

int i = atoi(row[0]);

long answer:

http://dev.mysql.com/doc/refman/5.0/en/mysql-fetch-row.html

Returns a MYSQL_ROW. You then have to iterate through the row to get each value. Those values are strings, so you'll need to convert them to int with atoi() . This is demonstrated in the code below (except the atoi() call) shamelessly stolen from the link above:

MYSQL_ROW row;
unsigned int num_fields;
unsigned int i;

num_fields = mysql_num_fields(result);
while ((row = mysql_fetch_row(result)))
{
   unsigned long *lengths;
   lengths = mysql_fetch_lengths(result);
   for(i = 0; i < num_fields; i++)
   {
       printf("[%.*s] ", (int) lengths[i],
              row[i] ? row[i] : "NULL");
   }
   printf("\n");
}