Mac OS Catalina下编译QT MySQL驱动遇问题求助

Hey there, let's work through this MySQL driver issue step by step— I've been stuck on this exact problem before, so I know how frustrating it can be when you're just trying to learn and hit a roadblock like this. Let's break it down simply:

First, Let's Understand the Root Problem #

Qt's online installer doesn't ship with the MySQL driver pre-compiled, so we need to build it ourselves. Your earlier attempts failed because you were working in the wrong directory and using incorrect qmake commands. Let's fix that.

Step 1: Install Qt's Source Code Component #

First, you need the Qt source files to compile the driver. Since you used the online installer:

• Open the Qt Maintenance Tool (it's in your Qt installation folder: /Users/Edward/Qt/MaintenanceTool.app)
• Select "Add or Remove Components"
• Expand the Qt 5.14.2 section, find and check the Sources option, then click "Apply" to install the source code.

Step 2: Navigate to the Correct MySQL Driver Source Directory #

Forget the /plugins/sqldrivers folder you were using earlier— that's where compiled drivers go, not where we build them. Head to the source code's MySQL driver folder instead:

cd /Users/Edward/Qt/5.14.2/Src/qtbase/src/plugins/sqldrivers/mysql

Step 3: Set Up Your Environment for Qt's qmake #

Make sure you're using the qmake that comes with your Qt 5.14.2 installation (not a system-wide one). First, check which qmake your terminal is using:

which qmake

If it doesn't show /Users/Edward/Qt/5.14.2/clang_64/bin/qmake, add Qt's bin folder to your PATH temporarily:

export PATH=/Users/Edward/Qt/5.14.2/clang_64/bin:$PATH

Step 4: Run qmake with the Correct MySQL Path #

Your earlier qmake command was missing two key things: pointing to the mysql.pro file, and using the exact path to your MySQL installation (not just /usr/local). Run this command:

qmake MYSQL_PREFIX=/usr/local/mysql-8.0.19-macos10.15-x86_64 mysql.pro

This tells qmake where your MySQL headers and libraries are located. If you get no errors here, you're on the right track!

Step 5: Compile and Install the Driver #

Now compile the driver with make, then install it to Qt's plugin folder:

make
make install

Wait for the compilation to finish— it might take a minute or two. Once done, the compiled libqsqlmysql.dylib file will automatically be copied to /Users/Edward/Qt/5.14.2/clang_64/plugins/sqldrivers.

Step 6: Verify the Driver Works #

Restart Qt Creator, then create a simple test project to check if the driver loads:

#include <QCoreApplication>
#include <QSqlDatabase>
#include <QDebug>

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);
    qDebug() << "Available drivers:" << QSqlDatabase::drivers();
    return a.exec();
}

Run this— you should now see QMYSQL and QMYSQL3 in the list of available drivers.

Quick Troubleshooting Tips #

• If you get a "cannot verify developer" error when running your app: Go to System Preferences > Security & Privacy, and click "Allow Anyway" for the driver file.
• Double-check that your MySQL installation is x86_64 (same as Qt's clang_64 build)— your MySQL 8.0.19 version for macOS 10.15 is correct here.
• You don't need the MySQL Connector/C++ you installed earlier— Qt's driver uses MySQL's client library directly, so that component can be ignored for this process.

内容的提问来源于stack exchange，提问作者EdBatt