Thread: My simple database program (help needed)

I haven't been studying c programming for that long but over the christmas break i was asked to code a simple database program.

Code:

/*-------------Library Headers--------------*/


#include <stdio.h>
#include <stdlib.h>
/*-----------function prototypes-------------*/


void menu(void);
void add(void);
void search(void);
void delete(void);




struct {
       int student_no;
       char firstname[15];
       char surname[15];
       int mark;
} student;
/*--------------Main------------------------*/
int main()
{
    FILE *pFile;
    pFile = fopen("database.txt","w");
    
    system("CLS");
    menu();
    getch();
    return 0;   
}
    
    
/*---------------Function menu-----------------*/
void menu()
{
int choice;
     printf("[1] Enter a student\n");
     printf("[2] Search a student by first name\n");
     printf("[3] Delete a student\n");
     printf("[4] Exit program\n");
     scanf("%d", &choice);
     
     switch(choice){
                    case 1: 
                         add();
                         break;
                    
                    case 2: 
                         search();
                         break;
                            
                    case 3: 
                         delete();
                         break;
                            
                    case 4: 
                         exit(0);
                         break;
                    
                    default: 
                         printf("Incorrect entry ");
                         menu();
                         break;
                    }
}


/*---------------Function Add-----------------*/
void add()
{
     FILE *pFile;
     
     char answer;
     int student_no;
     
     system("cls");
     
     printf("First Name: ");
     scanf("%s", student.firstname);
     printf("Surname: ");
     scanf("%s", student.surname);
     printf("\nAge: ");
     scanf("%d", &student.mark);
     
     pFile = fopen("database.txt","w");
     fprintf(pFile, "\n%s\t%s\t%d\t", student.firstname, student.surname, student.mark);
     fclose(pFile);
     
     printf("A student has been added successfully\n");
     printf("Are there any more people? \n[1] for yes \n[0] for no\n");
     scanf("%d", &answer);
     
     if (answer == 1)
     {
      add();           
     }
     if (answer == 0)
     {
      menu();           
     }
   
     
}


/*---------------Function Search -----------------*/
void search()
{
     int found, length;
     char studentname [15];
     FILE *pFile;
     
     printf("Enter student first name: ");
     scanf("%s", &studentname);
     printf("Searching for %s\n",studentname);
     
     found = 0;
     
     if ((pFile=fopen("database.txt","r"))==NULL)
     {
      printf("File is empty/missing");                                           
     }
     else
     {
         while(!feof(pFile) && found == 0)
         {
          fscanf(pFile,"\n%s\t%s\t%d",student.firstname, student.surname, student.mark);
          length = strlen (student.firstname);
          found == 1;                   
         }    
     }
     if (found)
     {
      printf("Record found.\n");
      printf("First Name: %s\nSurname: %s\nMark: %d \n",student.firstname, student.surname, student.mark);           
     }
     else
     {
      printf("not found");    
      getch();
     }
     
     
     
}
/*---------------Function Delete-----------------*/
void delete()
{
     
     
     
     
}

Problem 1: Looking at the file after compiling and adding a record, only occasionally something would show up

Problem 2: when i search for the record that is there the program stops responding and exits...

all help is appreciated

You may want to see about increasing your compiler warning level, if you're getting warnings you need to fix them. Here are the warnings and errors I got when I compiled your code:

main.c||In function ‘main’:|
main.c|26|warning: variable ‘pFile’ set but not used [-Wunused-but-set-variable]|
main.c||In function ‘add’:|
main.c|94|warning: format ‘%d’ expects argument of type ‘int *’, but argument 2 has type ‘char *’ [-Wformat=]|
main.c|77|warning: unused variable ‘student_no’ [-Wunused-variable]|
main.c||In function ‘search’:|
main.c|117|warning: format ‘%s’ expects argument of type ‘char *’, but argument 2 has type ‘char (*)[15]’ [-Wformat=]|
main.c|130|warning: format ‘%d’ expects argument of type ‘int *’, but argument 5 has type ‘int’ [-Wformat=]|
main.c|131|error: implicit declaration of function ‘strlen’ [-Wimplicit-function-declaration]|
main.c|131|warning: incompatible implicit declaration of built-in function ‘strlen’ [enabled by default]|
main.c|132|warning: statement with no effect [-Wunused-value]|
main.c|143|error: implicit declaration of function ‘getch’ [-Wimplicit-function-declaration]|
main.c|112|warning: variable ‘length’ set but not used [-Wunused-but-set-variable]|
||=== Build finished: 2 errors, 8 warnings (0 minutes, 0 seconds) ===|

Jim

How do I increase the compiler warning level? I use Dev C++

Side note, since you're using strlen() you ought to include string.h, and getch() doesn't seem to have a prototype declaration. Are you able to successfully compile a binary off your pasted code?