Are you tired of encountering the dreaded “"make: *** There is no rule to build target "sub-mysql". Stop." error when trying to create a MySQL driver with Qt? You’re not alone! Many developers have struggled with this issue, but fear not, dear reader, for we’re about to embark on a journey to resolve this pesky problem once and for all.
What’s Causing the Error?
The error message “"make: *** There is no rule to build target "sub-mysql". Stop."” typically occurs when you’re trying to build a Qt project that relies on the MySQL driver, but the build process can’t find the necessary dependencies. This can happen due to various reasons, including:
- Misconfigured Qt installation
- Incomplete or corrupted MySQL driver installation
- Inconsistent dependencies or libraries
- Incorrect project configuration or settings
Step-by-Step Solution
Fear not, dear reader, for we’re about to guide you through a series of steps to resolve the “"make: *** There is no rule to build target "sub-mysql". Stop."” error. Follow these instructions carefully, and you’ll be building your Qt project with MySQL driver in no time!
Step 1: Verify Your Qt Installation
First, ensure you have a properly installed Qt version that includes the necessary modules and tools. You can check your Qt installation by running the following command:
qt --versionMake sure you have the Qt 5.x or later version, as earlier versions might not support the MySQL driver.
Step 2: Install the MySQL Driver
Next, you need to install the MySQL driver for Qt. You can do this by running the following command:
sudo apt-get install libmysqlclient-devFor Windows users, download the MySQL Connector/C++ from the official MySQL website and follow the installation instructions.
Step 3: Configure Your Project
In your Qt project, add the following lines to your `.pro` file:
QT += sql
LIBS += -lmysqlclientThis tells Qt to include the SQL module and link against the MySQL client library.
Step 4: Update Your Qt Environment Variables
Update your Qt environment variables to include the MySQL driver. You can do this by running the following command:
export QT_PLUGIN_PATH=$QT_PLUGIN_PATH:/usr/lib/x86_64-linux-gnu/qt5/plugins/sqldriversFor Windows users, update the `QT_PLUGIN_PATH` environment variable to include the path to the MySQL driver plugin.
Step 5: Rebuild Your Project
Finally, rebuild your Qt project using the following command:
qmake && makeThis should recompile your project and include the MySQL driver.
Troubleshooting Tips
If you’re still encountering issues, here are some additional troubleshooting tips to help you resolve the “"make: *** There is no rule to build target "sub-mysql". Stop."” error:
- Check your MySQL driver installation and ensure it’s compatible with your Qt version.
- Verify that your Qt project configuration is correct and includes the necessary modules and libraries.
- Make sure your system has the necessary dependencies installed, such as `libssl-dev` and `libcrypto-dev`.
- Try cleaning and rebuilding your Qt project using the `qmake clean` and `qmake` commands.
Conclusion
With these steps, you should be able to resolve the “"make: *** There is no rule to build target "sub-mysql". Stop."” error and successfully create a Qt project with a MySQL driver. Remember to stay calm, follow the instructions carefully, and don’t hesitate to ask for help if you’re still encountering issues.
| Issue | Solution |
|---|---|
| Misconfigured Qt installation | Verify Qt installation and ensure it includes the necessary modules and tools |
| Incomplete or corrupted MySQL driver installation | Install the MySQL driver and ensure it’s compatible with your Qt version |
| Inconsistent dependencies or libraries | Verify system dependencies and libraries, and install missing ones as needed |
| Incorrect project configuration or settings | Update project configuration to include the necessary modules and libraries |
By following these steps and troubleshooting tips, you’ll be well on your way to creating a successful Qt project with a MySQL driver. Happy coding!
- Qt MySQL Driver Documentation
- MySQL Connector/C++ Documentation
- Qt SQL MySQL Driver Not Loaded StackOverflow Thread
Frequently Asked Question
Stuck with the “make: *** No rule to make target `sub-mysql’. Stop.” error while creating a MySQL driver with Qt?
What is the meaning of the “No rule to make target `sub-mysql'” error?
This error message indicates that the Qt build system (qmake) is unable to find a rule to build the `sub-mysql` target. This target is typically used to build the MySQL plugin for Qt. The error usually occurs when the MySQL plugin is not properly configured or installed.
How do I resolve the “No rule to make target `sub-mysql'” error?
To resolve this error, make sure you have the MySQL development libraries installed on your system. Then, configure the Qt build system to use the MySQL plugin by adding the following line to your `.pro` file: `QT += sql mysql`. Finally, run `qmake` and `make` again to rebuild your project.
Why do I need to install MySQL development libraries?
The MySQL development libraries are required to build the MySQL plugin for Qt. These libraries provide the necessary headers and libraries to connect to a MySQL database. Without them, the Qt build system cannot build the plugin, resulting in the “No rule to make target `sub-mysql'” error.
Can I use a different database plugin instead of MySQL?
Yes, Qt supports various database plugins, including PostgreSQL, SQLite, and more. If you don’t need to use MySQL specifically, you can use a different plugin by adding the corresponding module to your `.pro` file (e.g., `QT += sql postgres` for PostgreSQL). Make sure to install the required development libraries for the chosen database plugin.
How do I check if the MySQL plugin is properly installed and configured?
After installing the MySQL development libraries and configuring the Qt build system, you can check if the MySQL plugin is properly installed by running the `qmlplugindump` command with the `mysql` plugin as an argument: `qmlplugindump mysql`. If the plugin is installed correctly, you should see a list of plugin metadata and available drivers.
