Read Data from CSV and Put into Database - c

Question

I have a table with 6 columns and i have CSV Export like this with 6 entries per Line
me;val1;val2;val3;val4;val5;
me;val1;val2;val3;val4;val5;
I need to read these entries and Insert it into the SQLITE3 Database.So inorder to parse the CSV I use
void readcsv()
{
FILE* stream = fopen("input.csv", "r");
char line[1024];
while (fgets(line, 1024, stream))
{
char* tmp = strdup(line);
printf("Field 3 would be %s\n", getcsvfield(tmp, 3));
// NOTE strtok clobbers tmp
free(tmp);
}
}
//Used for parsing CSV
const char* getcsvfield(char* line, int num)
{
const char* tok;
for (tok = strtok(line, ";");
tok && *tok;
tok = strtok(NULL, ";\n"))
{
if (!--num)
return tok;
}
return NULL;
}
So will i have to call getcsvfield(tmp, fieldnumber) again and again in the Insert Query like this or is there a cleaner and efficient way.
execute("INSERT INTO table(a,b,c,d,e,f) VALUES('%s','%s','%s');",getcsvfield(tmp, 1),getcsvfield(tmp, 2),....... and so on
Please advise.

Answer 1

A more efficient method would be to parse the line once, creating an array of pointers to the tokens. You can then pass the array entries to the execute function like this
execute("INSERT INTO table(a,b,c,d,e,f) VALUES('%s','%s','%s');",token[0],token[1],...
Here's an example that reads lines from a file, breaks the line into tokens, and then prints the tokens.
#include <stdio.h>
#include <string.h>
int getTokens( char *line, char *token[], int maxt )
{
int i;
char *ptr = strtok(line, ";\n");
for ( i = 0; i < maxt; i++ )
{
if ( ptr == NULL )
return i;
token[i] = ptr;
ptr = strtok( NULL, ";\n" );
}
return i;
}
int main( void )
{
const int maxt = 6;
char line[1024];
char *token[maxt];
FILE *fp;
if ( (fp = fopen( "input.csv", "r" )) == NULL )
return 1;
while ( fgets(line, sizeof line, fp) != NULL )
{
int count = getTokens( line, token, maxt );
for ( int i = 0; i < count; i++ )
printf( "%d: '%s'\n", i, token[i] );
printf( "\n" );
}
fclose( fp );
}