A DuckDB Driver Plugin for Qt

Implements a driver plugin for Qt's SQL Databases for DuckDB.
Just copy the .dll/.so to your Qt plugin directory and you can add a "DUCKDB" database at any time. No other dependencies are required. You can use the full capabilities of DuckDB in your Qt program.

It also enables you to use duckdb in an easy way with Qt and Qt widgets, see the example below.

Example for creating a in memory database:

QSqlDatabase db = QSqlDatabase::addDatabase("DUCKDB");
db.setDatabaseName("test.db"); // creates a persistent database file "test.db"
db.open(); 
db.exec("CREATE TABLE employee (Name VARCHAR, Salary INTEGER);");

You can also use it to load csv or parquet (if duckdb was compiled with parquet support) files:

QSqlDatabase db = QSqlDatabase::addDatabase("DUCKDB");
db.open(); // no database name given -> creates a in-memory database
db.exec("CREATE TABLE new_tbl AS SELECT * FROM read_csv_auto('my_csv.csv');");

Example

In order to show a widget with a Sql content, you can use QSqlTableModel.

Here is an example on how to use the built-in Qt widget to show the contents of a DuckDB database in a grid widget

QSqlDatabase db = QSqlDatabase::addDatabase("DUCKDB");

db.open();
QSqlQuery query(db);
query.exec("CREATE TABLE employee (Name VARCHAR, Salary INTEGER);");
query.exec("INSERT INTO employee VALUES ('Paul', 5000);");
query.exec("INSERT INTO employee VALUES ('Bert', 5500);");
query.exec("INSERT INTO employee VALUES ('Tina', 6500);");

QSqlTableModel *model = new QSqlTableModel(nullptr, db);
model->setTable("employee");
model->select();

QTableView *view = new QTableView;
view->setModel(model);
view->show();

Which results in the following widget:

Full example can be found in the example directory

Build requirements

• DuckDB >= 0.7.1 (Version can be defined in the CMakeLists.txt)
• Qt 6 or 5

DuckDB will be linked statically.

For pre-build dlls, please choose the right version (See Qt Doc about plugin version)
tl;dr: don't use the plugin on Qt version below the version it was build for.

You can manually select the Qt Version with the cmake variable QT_VERSION== 5 or == 6. Otherwise, the auto detection will select the highest version.

Prebuild MSVC DLL in the artifacts

Github Actions will offer a MSVC DLL in the artifacts.

The artifact might be expired, but you can just fork this project and start the action on your own. This DLL in the qt plugin directory is all you need to use it, but I would also recommend the header, when you want to have direct access to the DuckDB C++ API.

License

LGPL v3

Based on Qt's sqlite driver code, which is licensed under the LGPL v3.
Based on DuckDB under the MIT license.