快速搭建 Qt 与 MySQL 的数据库应用（qt使用mysql）

With Qt and Qt Creator, developers can build robust, efficient and user-friendly applications. It implements a C++ graphical class library and serves as an application framework. Qt interacts with many databases, including MySQL, as an interface. In this article, we’ll show you how to quickly set up a Qt and MySQL database application.

First, install Qt and ensure that it is configured correctly. Then install MySql and a client for it, for example the mysql command line tool. Once MySQL is installed, create a database and load it with test data. This step is not always necessary, but is useful for testing your application.

Next, we’ll create a Qt project. Start Qt Creator and open the ‘New File or Project’ window. Select the template for a Qt GUI Application. Name the project and enter a directory for the project files. When prompted, select ‘Qt Widgets Application’ and press the ‘Continue’ button. Press the ‘Create’ button to generate the project files.

Now we’ll add a dialog to our project. Open the main window file and click on ‘File’ → ‘New File or Project’. Select the template for a Qt Dialog. Set a name for the dialog class and click ‘Next’. We then need to add the widgets of our dialog. Qt provides many widgets, such as labels, text fields, check boxes, list boxes, etc. Drag and drop the required widgets onto the form. Make sure to select the right properties for each widget, for example, for a text field we might set the maximum length to 255. We can also add layout to the widgets.

Once the dialog is designed, it’s time to add some code to connect the dialog to the database. To do this, we need to add the MySQL driver to the project. In Qt Creator, open the project file and select the ‘Projects’ tab. Under the ‘Build’ settings, select the MySQL driver and press ‘Add’.

Now we need to create a function to open a connection to the database. This function will also set the host name, user name and password required to access the database. It is important to note that we should never hardcode these values in the code, as this could be a security risk. Instead, these values should be stored in an external configuration file, which is read by the application at startup.

Finally, we will create a query to select and store data from the database. We can use the Qt SQL classes to simplify this task. Write a SQL statement to select the desired data and store it in a QVariantList. QVariantList is a list of QVariant objects that can be used to store data from the database.

With a few steps, we have created a Qt and MySQL database application. Qt’s power, efficiency and user-friendly features make it an ideal choice for such applications. With its rich library of widgets, layout and data manipulation classes, Qt can provide the necessary components for any application and make programming much easier.