sqlite and C

For anyone interested, I've thrown together a bit of code for using sqlite and c. As always, if anyone sees a problem, please point it out.

Code:

 
/* simple program to interface sqlite and C

   required: sqlite3.h and sqlite3.c

             compile sqlite3.c as part of your project
             #include "sqlite3.c" is incorrect

             source files - http://www.sqlite.org/download.html/sqlite-amalgamation-3071300.zip
*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sqlite/sqlite3.h>

typedef struct {
   int id;
   char name[33];
} vdata;

/* sqlite callback prototype; 
   this thing is not very useful on its own */

int some_function_name(void *, int, char **, char **);

int main(void) {

   sqlite3 *db;  // database object
   char *errmsg; /* sqlite error message you must
                    free(errmsg) if an error occurs) */
   int status;   // sqlite return status

   status = sqlite3_open("tryit.db", &db); /* creates a database file if
                                              it doesn't exist already */
											
   if(status != SQLITE_OK) { // show error and abort program
      fprintf(stderr, "error code: %d; error msg: %s", status, errmsg);
      free(errmsg);
      return(1);
   } else {   
        
      char cmd[BUFSIZ] = { 0 };	 
      int i = 1; 
      vdata void_d;

	  /* just want 10 records for testing; drop the table if it exists */
	  
	  if(sqlite3_exec(db, "drop table if exists tbl_test;", 0, 0, &errmsg) != SQLITE_OK) {
	     fprintf(stderr, "error msg: %s", errmsg);
             free(errmsg);
             sqlite3_close(db);
             return(1);
          } 
	  
	  // made it here, so try creating a table to test with */ 										  
											   
      sprintf(cmd, "create table if not exists tbl_test(\
                       id integer primary key autoincrement,\
                       name varchar(33) not null default '');");

      status = sqlite3_exec(db, cmd, 0, 0, &errmsg); // no callback, just check status

	  if(status != SQLITE_OK) { // show error and abort program
	     fprintf(stderr, "error code: %d; error msg: %s", status, errmsg);
             free(errmsg);
             sqlite3_close(db); // db was opened, so close it 
             return(1);
          }

	  // made it here, so try inserting some data

	  while(i <= 10) {
	     sprintf(cmd, "insert into tbl_test values(NULL, 'user %04d');", i);
             status = sqlite3_exec(db, cmd, 0, 0, &errmsg); // no callback, just check status

             if(status != SQLITE_OK) { // show error and abort program
                fprintf(stderr, "error code: %d; error msg: %s", status, errmsg);
                free(errmsg);
                sqlite3_close(db); // db was opened, so close it
                return(1);
             }

             ++i;
         }

	  // made it here, so use callback to see what was stored
	  // show the results where id is a multiple of 3
	  // should be in descending order based on id
	  
	  status = sqlite3_exec(db, "select * from tbl_test where id%3=0;", some_function_name, 0, &errmsg);

	  if(status != SQLITE_OK) { // show error and abort program
	     fprintf(stderr, "error code: %d; error msg: %s", status, errmsg);
             free(errmsg);
             sqlite3_close(db); // db was opened, so close it
             return(1);
          }

	  // make use of the void * parameter by fetching the 4 th record
	  // be sure to cast the appropriate type	  

	  sprintf(cmd, "select * from tbl_test where id=4 limit 1;");
	  status = sqlite3_exec(db, cmd, some_function_name, (vdata *)&void_d, &errmsg);

	  if(status != SQLITE_OK) {
	     fprintf(stderr, "error code: %d; error msg: %s", status, errmsg);
             free(errmsg);
             sqlite3_close(db);
             return(1);
         }

	  printf("\nrecord 4\nid = %d; name = %s\n\n", void_d.id, void_d.name);

	  // done with the database, so close it and exit program

	  sqlite3_close(db);
   }

   return 0;
}

int some_function_name(void *vptr, int count, char **col_data, char **col_name) {
   
   int i = 0;
   vdata *tmp = (vdata *)vptr;    
   
   while(i < count) {

      /* results are always strings; use conversion functions if
          needed.  to pass data between the callback and the main
          program, use the vptr.	     
      */
      
      if(tmp != NULL) {
	     if(strcmp(col_name[i], "id") == 0)
	        sscanf(col_data[i], "%d", &tmp->id);
             if(strcmp(col_name[i], "name") == 0)
                strcpy(tmp->name, col_data[i]);
      } else 	  		 	  
	     printf("%s = %s\n", col_name[i], col_data[i]);
	  
	  ++i;
   }
   
   putchar('\n');
   
   return 0;
}