MySQL的C语言连接问题（转北京网易）

[冷风]

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

main()
{
MYSQL *mysql;
MYSQL_RES *result;
MYSQL_ROW row;
unsigned int num_fields;
int i;
mysql = malloc(sizeof(MYSQL));
if ( !(mysql = mysql_connect(NULL, "localhost","root",NULL)))
fprintf(stderr, "Failed to connect to database: Errors: %s\n",
mysql_error(mysql));
fprintf(stderr, "Error: %s\n", mysql_error(mysql));
printf("server info: %s\n", mysql_get_server_info(mysql));
printf("host info: %s\n", mysql_get_host_info(mysql));


if (mysql_select_db(mysql, "wexam") )
{
printf("select db wrong: %s \n", mysql_error(mysql));
return;
}

mysql_query(mysql, "select * from UserTb");

result = mysql_store_result(mysql);

if (result == NULL)
{
printf("Error: %s\n", mysql_error(mysql));
return;
}

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]);
printf("\n");
}

mysql_free_result(result);
mysql_close(mysql);
}