SQL on MAC

LeoChen

I try to use sql with Qt, however, my code get the following errors:

Available drivers:
"QSQLITE"
"QMYSQL"
"QMYSQL3"
"QODBC"
"QODBC3"
"QPSQL"
"QPSQL7"
QSqlDatabase: QMYSQL driver not loaded
QSqlDatabase: available drivers: QSQLITE QMYSQL QMYSQL3 QODBC QODBC3 QPSQL QPSQL7

Here is my original code:

#include <QCoreApplication>
#include <QSqlDatabase>
#include <QDebug>
#include <QStringList>
#include <QSqlQuery>

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

    //List all available databases
    qDebug() << "Available drivers:";
    QStringList drivers = QSqlDatabase::drivers();
    for(auto t_s: drivers) {
        qDebug() << t_s;
    }


    // open mySql
    QSqlDatabase db = QSqlDatabase::addDatabase("QMYSQL");
    db.setHostName("localhost");
    db.setDatabaseName("mydata");
    db.setUserName("root");
    db.setPassword("");
    if(!db.open()) {
        qDebug() << "Failed to connect to root mysql admin";
    } else {
        qDebug() << "open";
    }

    QSqlQuery query(db);
    //varchar should has lenth
    query.exec("create table student(id int primary key, name varchar(20))");

    query.exec("insert into student values(1,'xiaogang')");
    query.exec("insert into student values(2,'xiaoming')");
    query.exec("insert into student values(3,'xiaohong')");

    query.exec("select id, name from student where id >= 2");

    while(query.next()) {
        int value0 = query.value(0).toInt();
        QString value1 = query.value(1).toString();
        qDebug() << value0 << value1;
    }

    return a.exec();
}

Did I miss something? thank you!

jsulm

@LeoChen Set QT_DEBUG_PLUGINS=1 environment variable and start your app. You should then see why the plug-in was not loaded (probably MySQL client library isn't available).

SGaist

Hi,

Which version of MySQL are you using ?
Where is it installed ?

LeoChen

@SGaist

Chens-MacBook-Pro:2017-03-31 chen$ mysql --version
mysql  Ver 14.14 Distrib 5.7.17, for osx10.12 (x86_64) using  EditLine wrapper
Chens-MacBook-Pro:2017-03-31 chen$ which mysql
/usr/local/bin/mysql

SGaist

Ok, then the plugin can't find its dependencies.

You can use install_name_tool on it to point it to your MySQL installation or rebuild the plugin following the doc recommendations.