UCS/sqlite_orm: ❤️ SQLite ORM light header only library for modern C++

examples/insert.cpp
132 строки4 KB
Yevgeniy Zakharov
added upsert clause
20 окт 2021, 15:34
20 окт 2021, 15:347e4bd36
/**
 *  This code is an implementation of this article https://www.tutorialspoint.com/sqlite/sqlite_insert_query.htm
 *  with C++ specific features like creating object and inserting within
 *  single line and separately, inserting a subclass object and inserting a vector.
 */

#include <sqlite_orm/sqlite_orm.h>
#include <string>
#include <iostream>

using std::cout;
using std::endl;

struct Employee {
    int id;
    std::string name;
    int age;
    std::string address;
    double salary;
};

struct DetailedEmployee : public Employee {
    std::string birthDate;
};

int main(int, char**) {
    using namespace sqlite_orm;

    auto storage = make_storage("insert.sqlite",
                                make_table("COMPANY",
                                           make_column("ID", &Employee::id, primary_key()),
                                           make_column("NAME", &Employee::name),
                                           make_column("AGE", &Employee::age),
                                           make_column("ADDRESS", &Employee::address),
                                           make_column("SALARY", &Employee::salary)));
    storage.sync_schema();
    storage.remove_all<Employee>();

    Employee paul{
        -1,
        "Paul",
        32,
        "California",
        20000.00,
    };

    //  insert returns inserted id
    paul.id = storage.insert(paul);

    storage.insert(Employee{
        -1,
        "Allen",
        25,
        "Texas",
        15000.00,
    });

    DetailedEmployee teddy;
    teddy.name = "Teddy";
    teddy.age = 23;
    teddy.address = "Norway";
    teddy.salary = 20000.00;

    //  to insert subclass object as a superclass you have to specify type explicitly
    teddy.id = storage.insert<Employee>(teddy);

    std::vector<Employee> otherEmployees;
    otherEmployees.push_back(Employee{
        -1,
        "Mark",
        25,
        "Rich-Mond",
        65000.00,
    });
    otherEmployees.push_back(Employee{
        -1,
        "David",
        27,
        "Texas",
        85000.00,
    });
    otherEmployees.push_back(Employee{
        -1,
        "Kim",
        22,
        "South-Hall",
        45000.00,
    });
    //  transaction is optional. It is used here to optimize sqlite usage - every insert opens
    //  and closes database. So triple insert will open and close the db three times.
    //  Transaction openes and closes the db only once.
    storage.transaction([&] {
        for(auto& employee: otherEmployees) {
            storage.insert(employee);
        }
        return true;  //  commit
    });

    Employee james{
        -1,
        "James",
        24,
        "Houston",
        10000.00,
    };
    james.id = storage.insert(james);

    cout << "---------------------" << endl;
    for(auto& employee: storage.iterate<Employee>()) {
        cout << storage.dump(employee) << endl;
    }

    //  INSERT INTO COMPANY(ID, NAME, AGE, ADDRESS, SALARY)
    //  VALUES (3, 'Sofia', 26, 'Madrid', 15000.0)
    //         (4, 'Doja', 26, 'LA', 25000.0)
    //  ON CONFLICT(ID) DO UPDATE SET NAME = excluded.NAME,
    //                                AGE = excluded.AGE,
    //                                ADDRESS = excluded.ADDRESS,
    //                                SALARY = excluded.SALARY

    storage.insert(
        into<Employee>(),
        columns(&Employee::id, &Employee::name, &Employee::age, &Employee::address, &Employee::salary),
        values(std::make_tuple(3, "Sofia", 26, "Madrid", 15000.0), std::make_tuple(4, "Doja", 26, "LA", 25000.0)),
        on_conflict(&Employee::id)
            .do_update(set(c(&Employee::name) = excluded(&Employee::name),
                           c(&Employee::age) = excluded(&Employee::age),
                           c(&Employee::address) = excluded(&Employee::address),
                           c(&Employee::salary) = excluded(&Employee::salary))));

    return 0;
}