#include <QSqlDatabase>
#include <QSqlQuery>
#include <QSqlError>

// 如果使用其他數(shù)據(jù)庫，可能需要包含對應(yīng)的頭文件，例如：
// #include <QMYSQLDriver> // 對于MySQL
// #include <QPSQLDriver> // 對于PostgreSQL

#include <QtSql>  
#include <QDebug>  
  
int main(int argc, char *argv[]) {  
    QCoreApplication a(argc, argv);  
  	//輸出所有已經(jīng)支持的數(shù)據(jù)庫驅(qū)動
    QStringList drivers = QSqlDatabase::drivers();  
    foreach (const QString &driver, drivers) {  
        qDebug() << driver;  
    }  
  
    return a.exec();  
}

QSqlDatabase db = QSqlDatabase::addDatabase("QSQLITE"); // 對于SQLite
// 或者
// QSqlDatabase db = QSqlDatabase::addDatabase("QMYSQL"); // 對于MySQL
// QSqlDatabase db = QSqlDatabase::addDatabase("QPSQL"); // 對于PostgreSQL

db.setHostName("localhost"); // 對于遠程數(shù)據(jù)庫，設(shè)置主機名或IP
db.setDatabaseName("/path/to/mydatabase.db"); // 對于SQLite，這是數(shù)據(jù)庫文件路徑；對于其他數(shù)據(jù)庫則是數(shù)據(jù)庫名
db.setUserName("username"); // 非SQLite數(shù)據(jù)庫的用戶名
db.setPassword("password"); // 非SQLite數(shù)據(jù)庫的密碼

if (!db.open()) {
    qDebug() << "Failed to connect to database: " << db.lastError().text();
    return false; // 連接失敗
}

QSqlQuery query;

// 插入數(shù)據(jù)
query.prepare("INSERT INTO MyTable (column1, column2) VALUES (?, ?)");
query.addBindValue(value1);
query.addBindValue(value2);
if (!query.exec()) {
    qDebug() << "Insert error: " << query.lastError().text();
} else {
    qDebug() << "Row inserted successfully.";
}

// 查詢數(shù)據(jù)
query.clear();
query.prepare("SELECT * FROM MyTable WHERE id = ?");
query.bindValue(0, someId);
if (query.exec()) {
    while (query.next()) {
        QString value1 = query.value(0).toString();
        int value2 = query.value(1).toInt();
        // ... 處理查詢結(jié)果 ...
    }
} else {
    qDebug() << "Select error: " << query.lastError().text();
}

db.close();

#include <QCoreApplication>
#include <QSqlDatabase>
#include <QSqlQuery>
#include <QSqlError>

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);

    QSqlDatabase db = QSqlDatabase::addDatabase("QSQLITE");
    db.setDatabaseName(":memory:"); // 使用內(nèi)存數(shù)據(jù)庫，也可以替換為實際文件路徑

    if (!db.open()) {
        qDebug() << "Cannot open database: " << db.lastError().text();
        return 1;
    }

    // 創(chuàng)建表
    QSqlQuery createQuery;
    createQuery.exec("CREATE TABLE IF NOT EXISTS MyTable (id INTEGER PRIMARY KEY, column1 VARCHAR(40), column2 INT)");

    // 插入數(shù)據(jù)
    QSqlQuery insertQuery;
    insertQuery.prepare("INSERT INTO MyTable (column1, column2) VALUES (?, ?)");
    insertQuery.addBindValue("Example Value");
    insertQuery.addBindValue(123);
    if (!insertQuery.exec()) {
        qDebug() << "Insert error: " << insertQuery.lastError().text();
    } else {
        qDebug() << "Row inserted successfully.";
    }

    // 查詢數(shù)據(jù)
    QSqlQuery selectQuery;
    selectQuery.prepare("SELECT * FROM MyTable");
    if (selectQuery.exec()) {
        while (selectQuery.next()) {
            QString column1Value = selectQuery.value(1).toString();
            int column2Value = selectQuery.value(2).toInt();
            qDebug() << "Column1: " << column1Value << ", Column2: " << column2Value;
        }
    } else {
        qDebug() << "Select error: " << selectQuery.lastError().text();
    }

    db.close();

    return a.exec();
}

#include <QApplication>
#include <QSqlDatabase>
#include <QSqlQuery>
#include <QDebug>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);

    // 打開第一個SQLite數(shù)據(jù)庫
    QSqlDatabase db1 = QSqlDatabase::addDatabase("QSQLITE");
    db1.setDatabaseName("first_db.sqlite");
    if (!db1.open()) {
        qDebug() << "Failed to open the first database: " << db1.lastError().text();
        return 1;
    }

    // 執(zhí)行第一個數(shù)據(jù)庫的查詢
    QSqlQuery query1(db1);
    query1.exec("CREATE TABLE IF NOT EXISTS Table1 (ID INTEGER PRIMARY KEY, Name TEXT)");
    if (!query1.isActive())
        qDebug() << "Error creating table in first DB: " << query1.lastError().text();

    // 打開第二個SQLite數(shù)據(jù)庫
    QSqlDatabase db2 = QSqlDatabase::addDatabase("QSQLITE");
    db2.setDatabaseName("second_db.sqlite");
    if (!db2.open()) {
        qDebug() << "Failed to open the second database: " << db2.lastError().text();
        db1.close();
        return 1;
    }

    // 執(zhí)行第二個數(shù)據(jù)庫的查詢
    QSqlQuery query2(db2);
    query2.exec("CREATE TABLE IF NOT EXISTS Table2 (ID INTEGER PRIMARY KEY, Name TEXT)");
    if (!query2.isActive())
        qDebug() << "Error creating table in second DB: " << query2.lastError().text();

    // 不論操作成功與否，記得在不再使用時關(guān)閉數(shù)據(jù)庫連接
    db1.close();
    db2.close();

    return a.exec();
}