Centos 7 中 QT出现QSqlDatabase: MYSQL driver not loaded
时间:2016-04-22 21:36 来源:linux.it.net.cn 作者:IT
系统版本 : Centos7
QT VERSION : 5.6
测试代码:
#include <iostream>
using namespace std;
#include <QApplication>
#include "gui/mainwindow.h"
#include <QSqlDatabase>
#include <QDebug>
#include <QSqlError>
#include <QSqlQuery>
using namespace std;
int main (int argc, char **argv) {
//输出可用数据库
QCoreApplication::addLibraryPath("/home/njq/dev_env/Qt5.6.0/5.6/gcc_64/plugins/sqldrivers");
qDebug()<<"available drivers:";
QStringList drivers = QSqlDatabase::drivers();
foreach(QString driver, drivers)
qDebug()<<driver;
//打开MySQL
QSqlDatabase data_base = QSqlDatabase::addDatabase("QMYSQL");
data_base.setHostName("192.168.0.200"); //设置主机地址
data_base.setPort(3306); //设置端口
data_base.setDatabaseName("alarmcenter"); //设置数据库名称
data_base.setUserName("root"); //设置用户名
data_base.setPassword("root"); //设置密码
if(!data_base.open())
qDebug()<<"failed to connect to mysql" << data_base.lastError ().text ();
else {
qDebug()<<"success";
QString strSQL = "SELECT alarm_id FROM alarm;";
QSqlQuery sql_query;
sql_query.prepare (strSQL);
sql_query.exec ();
while (sql_query.next ()) {
int id = sql_query.value (0).toInt ();
qDebug () << id;
}
}
}
出现了如下的错误:
QSqlDatabase: MYSQL driver not loaded
QSqlDatabase: available drivers: QSQLITE QMYSQL QMYSQL3 QPSQL QPSQL7
QSqlDatabase: an instance of QCoreApplication is required for loading driver plugins
failed to connect to mysql "Driver not loaded Driver not loaded"
查看QT的安装目录
~/dev_env/Qt5.6.0/5.6/gcc_64/plugins/sqldrivers
有一个文件：
libqsqlmysql.so
使用ldd命令检查下依赖
[xxx@localhost sqldrivers]$ ldd libqsqlmysql.so
linux-vdso.so.1 => (0x00007ffcf65b4000)
libmysqlclient_r.so.16 => not found
libz.so.1 => /lib64/libz.so.1 (0x00007f452c898000)
看到 libmysqlclient_r.so.16 这个so文件的依赖没有找到 通过查找资料，发现如下解决办法
重新编译MySQL驱动
[njq@localhost mysql]$ cd ~/dev_env/Qt5.6.0/5.6/Src/qtbase/src/plugins/sqldrivers/mysql
[xxx@localhost mysql]$ ~/dev_env/Qt5.6.0/5.6/gcc_64/bin/qmake #因为没有配置qmake路径，所以用了全路径
[xxx@localhost mysql]$ make
看到编译后的最后一行
mv -f libqsqlmysql.so ../../../../plugins/sqldrivers/
把这个生成的libqsqlmysql.so覆盖到……./Qt5.6.0/5.6/gcc_64/plugins/sqldrivers
[xxx@localhost sqldrivers]$ mv libqsqlmysql.so ~/dev_env/Qt5.6.0/5.6/gcc_64/plugins/sqldrivers/
然后再查看libqsqlmysql.so的依赖
[xxx@localhost sqldrivers]$ ldd libqsqlmysql.so
linux-vdso.so.1 => (0x00007fffc437c000)
libmysqlclient.so.18 => /usr/lib64/mysql/libmysqlclient.so.18 (0x00007f3de67bc000)
libz.so.1 => /lib64/libz.so.1 (0x00007f3de65a5000)
libcrypt.so.1 => /lib64/libcrypt.so.1 (0x00007f3de636e000)
libnsl.so.1 => /lib64/libnsl.so.1 (0x00007f3de6155000)
libssl.so.10 => /lib64/libssl.so.10 (0x00007f3de5ee7000)
libcrypto.so.10 => /lib64/libcrypto.so.10 (0x00007f3de5aff000)
libQt5Sql.so.5 => not found
libQt5Core.so.5 => not found
libpthread.so.0 => /lib64/libpthread.so.0 (0x00007f3de58e2000)
libstdc++.so.6 => /lib64/libstdc++.so.6 (0x00007f3de55da000)
libm.so.6 => /lib64/libm.so.6 (0x00007f3de52d7000)
libgcc_s.so.1 => /lib64/libgcc_s.so.1 (0x00007f3de50c1000)
libc.so.6 => /lib64/libc.so.6 (0x00007f3de4d00000)
libdl.so.2 => /lib64/libdl.so.2 (0x00007f3de4afb000)
libfreebl3.so => /lib64/libfreebl3.so (0x00007f3de48f8000)
libgssapi_krb5.so.2 => /lib64/libgssapi_krb5.so.2 (0x00007f3de46ac000)
libkrb5.so.3 => /lib64/libkrb5.so.3 (0x00007f3de43c6000)
libcom_err.so.2 => /lib64/libcom_err.so.2 (0x00007f3de41c2000)
libk5crypto.so.3 => /lib64/libk5crypto.so.3 (0x00007f3de3f90000)
/lib64/ld-linux-x86-64.so.2 (0x00007f3de6ee3000)
libkrb5support.so.0 => /lib64/libkrb5support.so.0 (0x00007f3de3d80000)
libkeyutils.so.1 => /lib64/libkeyutils.so.1 (0x00007f3de3b7c000)
libresolv.so.2 => /lib64/libresolv.so.2 (0x00007f3de3962000)
libselinux.so.1 => /lib64/libselinux.so.1 (0x00007f3de373c000)
libpcre.so.1 => /lib64/libpcre.so.1 (0x00007f3de34db000)
liblzma.so.5 => /lib64/liblzma.so.5 (0x00007f3de32b5000)
看到问题已经搞定
重新运行程序，看到如下结果
available drivers:
"QSQLITE"
"QMYSQL"
"QMYSQL3"
"QPSQL"
"QPSQL7"
success
171118
171119
171120
171121
171122
171123
171124
171125
171126
171127
171128
171129
171130
171131
171132
171133
171134
171135
171136
(责任编辑：IT)
系统版本 : Centos7 QT VERSION : 5.6 测试代码: #include <iostream> using namespace std; #include <QApplication> #include "gui/mainwindow.h" #include <QSqlDatabase> #include <QDebug> #include <QSqlError> #include <QSqlQuery> using namespace std; int main (int argc, char **argv) { //输出可用数据库 QCoreApplication::addLibraryPath("/home/njq/dev_env/Qt5.6.0/5.6/gcc_64/plugins/sqldrivers"); qDebug()<<"available drivers:"; QStringList drivers = QSqlDatabase::drivers(); foreach(QString driver, drivers) qDebug()<<driver; //打开MySQL QSqlDatabase data_base = QSqlDatabase::addDatabase("QMYSQL"); data_base.setHostName("192.168.0.200"); //设置主机地址 data_base.setPort(3306); //设置端口 data_base.setDatabaseName("alarmcenter"); //设置数据库名称 data_base.setUserName("root"); //设置用户名 data_base.setPassword("root"); //设置密码 if(!data_base.open()) qDebug()<<"failed to connect to mysql" << data_base.lastError ().text (); else { qDebug()<<"success"; QString strSQL = "SELECT alarm_id FROM alarm;"; QSqlQuery sql_query; sql_query.prepare (strSQL); sql_query.exec (); while (sql_query.next ()) { int id = sql_query.value (0).toInt (); qDebug () << id; } } } 出现了如下的错误: QSqlDatabase: MYSQL driver not loaded QSqlDatabase: available drivers: QSQLITE QMYSQL QMYSQL3 QPSQL QPSQL7 QSqlDatabase: an instance of QCoreApplication is required for loading driver plugins failed to connect to mysql "Driver not loaded Driver not loaded" 查看QT的安装目录 ~/dev_env/Qt5.6.0/5.6/gcc_64/plugins/sqldrivers 有一个文件： libqsqlmysql.so 使用ldd命令检查下依赖 [xxx@localhost sqldrivers]$ ldd libqsqlmysql.so linux-vdso.so.1 => (0x00007ffcf65b4000) libmysqlclient_r.so.16 => not found libz.so.1 => /lib64/libz.so.1 (0x00007f452c898000) 看到 libmysqlclient_r.so.16 这个so文件的依赖没有找到 通过查找资料，发现如下解决办法 重新编译MySQL驱动 [njq@localhost mysql]$ cd ~/dev_env/Qt5.6.0/5.6/Src/qtbase/src/plugins/sqldrivers/mysql [xxx@localhost mysql]$ ~/dev_env/Qt5.6.0/5.6/gcc_64/bin/qmake #因为没有配置qmake路径，所以用了全路径 [xxx@localhost mysql]$ make 看到编译后的最后一行 mv -f libqsqlmysql.so ../../../../plugins/sqldrivers/ 把这个生成的libqsqlmysql.so覆盖到……./Qt5.6.0/5.6/gcc_64/plugins/sqldrivers [xxx@localhost sqldrivers]$ mv libqsqlmysql.so ~/dev_env/Qt5.6.0/5.6/gcc_64/plugins/sqldrivers/ 然后再查看libqsqlmysql.so的依赖 [xxx@localhost sqldrivers]$ ldd libqsqlmysql.so linux-vdso.so.1 => (0x00007fffc437c000) libmysqlclient.so.18 => /usr/lib64/mysql/libmysqlclient.so.18 (0x00007f3de67bc000) libz.so.1 => /lib64/libz.so.1 (0x00007f3de65a5000) libcrypt.so.1 => /lib64/libcrypt.so.1 (0x00007f3de636e000) libnsl.so.1 => /lib64/libnsl.so.1 (0x00007f3de6155000) libssl.so.10 => /lib64/libssl.so.10 (0x00007f3de5ee7000) libcrypto.so.10 => /lib64/libcrypto.so.10 (0x00007f3de5aff000) libQt5Sql.so.5 => not found libQt5Core.so.5 => not found libpthread.so.0 => /lib64/libpthread.so.0 (0x00007f3de58e2000) libstdc++.so.6 => /lib64/libstdc++.so.6 (0x00007f3de55da000) libm.so.6 => /lib64/libm.so.6 (0x00007f3de52d7000) libgcc_s.so.1 => /lib64/libgcc_s.so.1 (0x00007f3de50c1000) libc.so.6 => /lib64/libc.so.6 (0x00007f3de4d00000) libdl.so.2 => /lib64/libdl.so.2 (0x00007f3de4afb000) libfreebl3.so => /lib64/libfreebl3.so (0x00007f3de48f8000) libgssapi_krb5.so.2 => /lib64/libgssapi_krb5.so.2 (0x00007f3de46ac000) libkrb5.so.3 => /lib64/libkrb5.so.3 (0x00007f3de43c6000) libcom_err.so.2 => /lib64/libcom_err.so.2 (0x00007f3de41c2000) libk5crypto.so.3 => /lib64/libk5crypto.so.3 (0x00007f3de3f90000) /lib64/ld-linux-x86-64.so.2 (0x00007f3de6ee3000) libkrb5support.so.0 => /lib64/libkrb5support.so.0 (0x00007f3de3d80000) libkeyutils.so.1 => /lib64/libkeyutils.so.1 (0x00007f3de3b7c000) libresolv.so.2 => /lib64/libresolv.so.2 (0x00007f3de3962000) libselinux.so.1 => /lib64/libselinux.so.1 (0x00007f3de373c000) libpcre.so.1 => /lib64/libpcre.so.1 (0x00007f3de34db000) liblzma.so.5 => /lib64/liblzma.so.5 (0x00007f3de32b5000) 看到问题已经搞定 重新运行程序，看到如下结果 available drivers: "QSQLITE" "QMYSQL" "QMYSQL3" "QPSQL" "QPSQL7" success 171118 171119 171120 171121 171122 171123 171124 171125 171126 171127 171128 171129 171130 171131 171132 171133 171134 171135 171136 (责任编辑：IT) |