First, the simple example code, then a line by line description:
#include <iostream>
using namespace stactiverecord;
using namespace std;
Sar_Dbi * Sar_Dbi::dbi = Sar_Dbi::makeStorage("sqlite://:memory:");
class Person : public Record<Person> {
public:
static string classname;
int age;
string fullname;
Person() : Record<Person>() {
age = 0;
fullname = "Unknown";
};
Person(int id) : Record<Person>(id) {
get("age", age, 0);
get("fullname", fullname, "Unknown");
};
void save() {
set("age", age);
set("fullname", fullname);
Record<Person>::save();
};
void sayage() {
std::cout << "I'm " << fullname << " and I'm " << age << " years old.\n";
};
};
string Person::classname = "person";
int main() {
Person bob;
bob.fullname = "Robert Somethingorother";
bob.age = 50;
bob.save();
ObjGroup<Person> people = Person::find(Q("age", between(40, 100)) && Q("fullname", startswith("Robert")));
people[0].sayage();
cout << "Name is: " << people[0].fullname << "\n";
delete Sar_Dbi::dbi; // only cleanup necessary
return 0;
};
Description
First, open the database connection (more information can be found on the usage page:
Sar_Dbi * Sar_Dbi::dbi = Sar_Dbi::makeStorage("sqlite://:memory:");
All object classes must extend the base Record template. They must also specify a static public string variable named classname. The classname should be the name of the class (it must contain only upper and lowercase letters, no numbers or other characters). The following is the simplest and object can get:
class Person : public Record<Person> {
public:
static string classname;
Person() : Record<Person>() {};
Person(int id) : Record<Person>(id) {};
};
string Person::classname = "person";
As in the example, there are two public class attributes, age and fullname. These are initialized in the two constructors (one for a new object, the other for an existing one identified by its id). In the constructor that accepts an id, the attributes are initialized to either the values stored in the database for the given object or with a default value (0 and Unknown) if no value was given when the object was saved.
Person() : Record<Person>() {
age = 0;
fullname = "Unknown";
};
Person(int id) : Record<Person>(id) {
// Give a default value of 0 if age isn't set
get("age", age, 0);
// Give a default value of Unkown if fullname isn't not set
get("fullname", fullname, "Unknown");
};
When the object’s save method is called, it’s age and fullname are first set (using the parent’s method set), and then the object is saved using the parent’s save method. Note that the object’s set methods are not protected and can be called outside of the class (say, for instance, if you don’t want to have class attribute variables at all).
void save() {
set("age", age);
set("fullname", fullname);
Record<Person>::save();
};
For instance, the following code:
Person bob;
bob.fullname = "Robert Somethingorother";
bob.age = 50;
bob.save();
could be implemented using the following instead:
Person bob;
bob.set("fullname", "Robert Somethingorother");
bob.set("age", 50);
bob.save();
which would eliminate the need for an overwritten save method and instance variables.
The following is an example of a complicated query - more examples can be found on the usage page.
ObjGroup<Person> people = Person::find(Q("age", between(40, 100)) && Q("fullname", startswith("Robert")));