**Course Title:** PyQt6 Application Development **Section Title:** Integrating Databases with PyQt6 **Topic:** Building a CRUD app with SQLite and displaying data in a table.(Lab topic) **Objective:** In this hands-on lab, we will build a simple CRUD (Create, Read, Update, and Delete) application using PyQt6 and SQLite. We will demonstrate how to create a database connection, perform CRUD operations, and display the data in a table. **Materials Needed:** * Python 3.8+ * PyQt6 * SQLite (comes bundled with Python) **Part 1: Create a Database Connection** To start, we need to create a database connection using the `QSqlDatabase` class. This class provides a way to connect to various databases, including SQLite. ```python import sys from PyQt6.QtSql import QSqlDatabase, QSqlQuery from PyQt6.QtWidgets import QApplication def create_database_connection(): database = QSqlDatabase.addDatabase("QSQLITE") database.setDatabaseName("test.db") if database.open(): print("Connected to database") else: print("Failed to connect to database") sys.exit(1) if __name__ == "__main__": app = QApplication([]) create_database_connection() ``` In the above code, we create a new database connection using `QSqlDatabase.addDatabase("QSQLITE")`. We then set the database name to "test.db" and open the connection using the `open()` method. **Part 2: Perform CRUD Operations** Now that we have a database connection, we can perform CRUD operations. We will create a simple table with two columns: "id" and "name". ```python def create_table(): query = QSqlQuery() query.exec("CREATE TABLE IF NOT EXISTS users (id INTEGER PRIMARY KEY, name TEXT NOT NULL)") if query.isActive(): print("Table created successfully") else: print("Failed to create table") sys.exit(1) def insert_user(name): query = QSqlQuery() query.prepare("INSERT INTO users (name) VALUES (:name)") query.bindValue(":name", name) if query.exec(): print("User inserted successfully") else: print("Failed to insert user") sys.exit(1) def select_users(): query = QSqlQuery() query.exec("SELECT * FROM users") if query.isActive(): while query.next(): print(f"ID: {query.value(0)}, Name: {query.value(1)}") else: print("Failed to select users") sys.exit(1) def update_user(id, name): query = QSqlQuery() query.prepare("UPDATE users SET name = :name WHERE id = :id") query.bindValue(":id", id) query.bindValue(":name", name) if query.exec(): print("User updated successfully") else: print("Failed to update user") sys.exit(1) def delete_user(id): query = QSqlQuery() query.prepare("DELETE FROM users WHERE id = :id") query.bindValue(":id", id) if query.exec(): print("User deleted successfully") else: print("Failed to delete user") sys.exit(1) if __name__ == "__main__": app = QApplication([]) create_table() insert_user("John Doe") select_users() update_user(1, "Jane Doe") select_users() delete_user(1) select_users() ``` In the above code, we create a table using the `CREATE TABLE` SQL statement. We then insert a user using the `INSERT INTO` SQL statement. We select all users using the `SELECT *` SQL statement. We update a user using the `UPDATE` SQL statement. Finally, we delete a user using the `DELETE FROM` SQL statement. **Part 3: Display Data in a Table** To display the data in a table, we can use the `QTableView` widget. ```python import sys from PyQt6.QtSql import QSqlDatabase, QSqlQuery, QSqlTableModel from PyQt6.QtWidgets import QApplication, QTableView def display_data(): database = QSqlDatabase.addDatabase("QSQLITE") database.setDatabaseName("test.db") model = QSqlTableModel() model.setTable("users") model.select() view = QTableView() view.setModel(model) view.show() if __name__ == "__main__": app = QApplication([]) display_data() sys.exit(app.exec()) ``` In the above code, we create a new database connection and set the database name. We then create a `QSqlTableModel` instance and set the table name to "users". We select all data from the table using the `select()` method. We then create a `QTableView` widget and set the model using the `setModel()` method. Finally, we show the view using the `show()` method. **Conclusion:** In this hands-on lab, we built a simple CRUD application using PyQt6 and SQLite. We created a database connection, performed CRUD operations, and displayed the data in a table using `QTableView`. This lab demonstrated how to integrate a database with PyQt6 and perform basic operations. **Additional Resources:** * [SQLite Documentation](https://www.sqlite.org/docs.html) * [PyQt6 Documentation](https://www.riverbankcomputing.com/software/pyqt/intro) If you have any questions or need further clarification, please leave a comment below.