qt 5.15.2连接postgresql9.4数据库功能

执行后显示效果：

"QSQLITE"
"QODBC"
"QODBC3"
"QPSQL"
"QPSQL7"
connected success to postgresql9.4
"admin"   "1"

注意事项:

连接postgresql9.4数据库需要copy下列文件到执行程序所在目录下
-----------qt自带的-----------------
qsqlpsqld.dll-----------postgresql的-------------------
libpq.dll
ssleay32.dll
libeay32.dll
libintl.dll---------.pro 添加行-------------------
QT       += sql# custom add postgresql .h and .lib file path  by hsg
INCLUDEPATH += "D:/PostgreSQL/9.4/include"
LIBS +="D:/PostgreSQL/9.4/lib/libpq.lib"

.pro

QT       += core gui opengl 3dcore 3drender 3dinput 3dextras
QT       += sql
greaterThan(QT_MAJOR_VERSION, 4): QT += widgetsCONFIG += c++17# You can make your code fail to compile if it uses deprecated APIs.
# In order to do so, uncomment the following line.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0SOURCES += \dialog_fbx2glb.cpp \dialog_osgb_to_b3dm.cpp \leftorbitcameracontroller.cpp \main.cpp \mainwindow.cpp \qleftcameracontroller.cpp \scene.cppHEADERS += \LeftOrbitCameraControllerPrivate.h \dialog_fbx2glb.h \dialog_osgb_to_b3dm.h \leftorbitcameracontroller.h \mainwindow.h \qleftcameracontroller.h \scene.hFORMS += \dialog_fbx2glb.ui \dialog_osgb_to_b3dm.ui \mainwindow.ui# custom add postgresql .h and .lib file path  by hsg
INCLUDEPATH += "D:/PostgreSQL/9.4/include"
LIBS +="D:/PostgreSQL/9.4/lib/libpq.lib"# Default rules for deployment.
qnx: target.path = /tmp/$${TARGET}/bin
else: unix:!android: target.path = /opt/$${TARGET}/bin
!isEmpty(target.path): INSTALLS += targetDISTFILES += \images/211.ico \images/Clear2.ico \images/File.ico \images/Open.ico \images/opendir.png \images/openfile.png \readme.txt

man.cpp

#include "mainwindow.h"#include <QApplication>
#include <QSqlDatabase>
#include <QDebug>
#include <QSqlQuery>
#include <libpq-fe.h>void printSqlDrivers();  //先定义
void testConnectSQL();int main(int argc, char *argv[])
{QApplication a(argc, argv);QCoreApplication::addLibraryPath(QCoreApplication::applicationDirPath() +"/plugins");//QApplication::addLibraryPath(QApplication::applicationDirPath() +"/plugins");//MainWindow w;//w.show();printSqlDrivers();   //调用testConnectSQL();    //测试连接postgresql9.4return a.exec();
}//后函数实现
void printSqlDrivers()
{QStringList drivers=QSqlDatabase::drivers();foreach(QString driver,drivers){qDebug()<<driver;}/*"QSQLITE""QODBC""QODBC3""QPSQL""QPSQL7"*///上面输出有QPSQL关键字才能继续操作testConnectSQL()}
void testConnectSQL()
{QSqlDatabase db=QSqlDatabase::addDatabase("QPSQL");db.setHostName("192.168.30.33");db.setDatabaseName("pg-sys");db.setPort(5432);db.setUserName("postgres");db.setPassword("1");bool ok=db.open();if(ok){//QMessageBox::information(nullptr,"infor","success");qDebug()<<"connected success to postgresql9.4";}else{//QMessageBox::information(nullptr,"infor","open failed");qDebug()<<"open failed";//报错可能为//1.copy sql相关的库到可执行目录下，//或2.db的连接有错误的参数//或3.qt的psql驱动版本不兼容(需重新编译qt 5.15.2安装自带源码下插件psql.pro工程 需引用psql安装libpq.dll库)}QSqlQuery q=db.exec("select * from sys_user order by user_id asc");while(q.next()){QString userId=q.value("user_id").toString();QString userName=q.value("user_name").toString();qDebug()<<userName<<" "<<userId;}db.close();}