i am at the point in an app where i will be accessing a database (AISC steel section properties). will i need a seperate utilitie to open a database and access it by field name etc...
or does C++ have a library function that will allow searching a database by row or column.
i have no code to offer because i have no idea how this is even attempted.
int i_have _a_value()
look in the data base for 5 values
1 = i_have _a_value
2 = next_two_higher_values
2 = next_two_lower_values
retrieve the entire rows containing these values
} // or something like this
the data base will be several hundred rows and about 20 columns.
where do i start?
Ask your database vendor if he provides you with an interface to C/C++. It very likely he will. It's a set of functions that you can use to access the data stored in the database. I can't tell you more, as the actual implementation is database specific. For Oracle for example, it's the OCI, Oracle Call Interface. For other vendors, there might be other solutions.
Are you using a professional/commercal database? If so nvoigt already answered your point.
Or do you want to create a simple database yourself?
You could make a structure or class to hold all the data for each object.
Then make an array or whatever you want with this class.
Using FILE * 's you can read and write entier arrays at once
That will make an array, write it to a file.
FILE * myfile;
for( i=0 ; i<500 ; i++)
myfile = fopen("database","wb");//write/binary
fwrite(array,sizeof(int),500,myfile); //this should write the whole array to the text file
fclose(myfile); //close the file.
//do stuff here
myfile = fopen("database","rb"); //open the file for reading
fread(array2,sizeof(int),500,myfile); //read in our array we wrote earlier
Then the file is closed.
The file can then be opened, and read in with one line