Qt PostgreSQL 範例

Qt PostgreSQL 範例

=== 測試環境
OS: Windows 7
Qt Verstion: 5.5.0
Compiler: Visual Studio 2013

OS: Arch Linux 4.1.6
Qt Version: 5.5.0
Compiler: GCC 5.2.0

=== 程式範例

	QSqlDatabase db = QSqlDatabase::addDatabase("QPSQL");
	db.setHostName("127.0.0.1");
	db.setDatabaseName("FirstDB");
	db.setUserName("demo");
	db.setPassword("password");
	bool ok = db.open();
	if (ok)
	{
	QSqlQuery query("SELECT \"SID\", \"Account\", \"CreateDate\", \"LoginTimes\" FROM \"Account\"");
	while (query.next())
	{
	qWarning() << query.value(0).toString();
	qWarning() << query.value(1).toString();
	qWarning() << query.value(2).toString();
	qWarning() << query.value(3).toString();
	}
	qDebug() << query.lastError().text();
	}

view raw sql.cpp hosted with ❤ by GitHub

=== 錯誤訊息
QSqlDatabase: QPSQL driver not loaded
QSqlDatabase: available drivers: QSQLITE QMYSQL QMYSQL3 QODBC QODBC3 QPSQL QPSQL7

在 Windows，確認下列檔案
MyAppDir\sqldrivers\qsqlpsql.dll
MyAppDir\libpq.dll
MyAppDir\libeay32.dll
MyAppDir\ssleay32.dll

在 linux，確認 qt project file 加上
INCLUDEPATH+=/usr/include/pgsql
LIBS+=-L/usr/lib -lpq

=== 資料來源
Qt Documentation - SQL Database Drivers
http://doc.qt.io/qt-5/sql-driver.html

Qt: SELECT-Query to PostgreSQL-Server always responses with NULL
http://stackoverflow.com/questions/13633055/qt-select-query-to-postgresql-server-always-responses-with-null

QT5: Failed to load psql driver in windows
http://stackoverflow.com/questions/20884010/qt5-failed-to-load-psql-driver-in-windows