void CreateUserTable()
{
    QSqlQuery query;
    QString str  = "CREATE TABLE user ( "
                            "id INTEGER PRIMARY KEY NOT NULL, "
                            "username   VARCHAR(20), "
                            "password  VARCHAR(20), "
                            "UNIQUE (username) "
                        ");";
    if (!query.exec(str)) {
        qDebug() << "Unable to create table";
    }else{
        qDebug() << "create user table";
    }
}

void CreateAmountTable()
{
    QSqlQuery query;
    QString str  = "CREATE TABLE amount ( "
                            "id INTEGER PRIMARY KEY NOT NULL, "
                            "reason  VARCHAR(144), "
                            "summ VARCHAR(144), "
                            "author  INTEGER, "
                            "FOREIGN KEY(author) REFERENCES user(id)"
                        ");";
    if (!query.exec(str)) {
        qDebug() << "Unable to create table";
    }else{
        qDebug() << "create Amount table";
    }
}
void CreateCostsTable()
{
    QSqlQuery query;
    QString str  = "CREATE TABLE costs ( "
                            "id INTEGER PRIMARY KEY NOT NULL, "
                            "reason  VARCHAR(144), "
                            "summ VARCHAR(144) "
                            "author  INTEGER, "
                            "FOREIGN KEY(author) REFERENCES user(id)"
                        ");";
    if (!query.exec(str)) {
        qDebug() << "Unable to create table";
    }else{
        qDebug() << "create cost table";
    }
}