我是JavaFx和数据库的新手。我试图将一个数据库中的两个或多个表填充到JavaFx tableview中。我怎样才能做到这一点？这就是我到目前为止所拥有的。
1）这是我的GeneralData.java
public class GeneralData {
private final StringProperty Year;
private final StringProperty Month;
private final StringProperty Temperature;
private final StringProperty Wind_Lowest;
private final StringProperty Wind_Highest;
private final StringProperty MinUVI;
private final StringProperty MaxUVI;
private final StringProperty MinAQI;
private final StringProperty MaxAQI;
private final StringProperty Humidity;
private final StringProperty Snowfall;
private final StringProperty Pressure;
public GeneralData(String year, String month, String temperature,
String windlo, String Windhi,String minUVI, String maxUVI, String
minAQI, String maxAQI, String humidity, String snowfall, String
pressure){
this.Year = new SimpleStringProperty(year);
this.Month = new SimpleStringProperty(month);
this.Temperature = new SimpleStringProperty(temperature);
this.Wind_Lowest = new SimpleStringProperty(windlo);
this.Wind_Highest= new SimpleStringProperty(Windhi);
this.MinUVI = new SimpleStringProperty(minUVI);
this.MaxUVI = new SimpleStringProperty(maxUVI);
this.MinAQI = new SimpleStringProperty(minAQI);
this.MaxAQI = new SimpleStringProperty(maxAQI);
this.Humidity = new SimpleStringProperty(humidity);
this.Snowfall = new SimpleStringProperty(snowfall);
this.Pressure = new SimpleStringProperty(pressure);
}
2）这是我的GeneralMode.java
public class GeneralModel {
Connection conn;
public GeneralModel() {
try {
this.conn = dbConnection.getConnection();
} catch (SQLException e) {
e.printStackTrace();
}
if (this.conn == null) {
System.exit(1);
}
}
public boolean isDatabasedConnected() {
return this.conn != null;
}
}
3）这是我的generalController.java
public class GeneralController implements Initializable {
GeneralModel generalModel = new GeneralModel();
@FXML
private Label dbStatus;
@FXML
private TextField miniField;
@FXML
private TextField maxField;
@FXML
private TableView<GeneralData> weatherTracerTable;
@FXML
private TableColumn<GeneralData, String> yearCol;
@FXML
private TableColumn<GeneralData, String> monthCol;
@FXML
private TableColumn<GeneralData, String> temperatureCol;
@FXML
private TableColumn<GeneralData, String> windLowCol;
@FXML
private TableColumn<GeneralData, String> windHighCol;
@FXML
private TableColumn<GeneralData, String> minUVICol;
@FXML
private TableColumn<GeneralData, String> maxUVICol;
@FXML
private TableColumn<GeneralData, String> minAQICol;
@FXML
private TableColumn<GeneralData, String> maxAQICol;
@FXML
private TableColumn<GeneralData, String> humidityCol;
@FXML
private TableColumn<GeneralData, String> snowFallCol;
@FXML
private TableColumn<GeneralData, String> pressureCol;
@FXML
private ComboBox Year;
@FXML
private ComboBox Type;
private dbConnection dbconn;
private ObservableList<GeneralData> data;
private String sql = "SELECT * FROM weather_tracer";
public void initialize(URL url, ResourceBundle rb) {
if (this.generalModel.isDatabasedConnected()) {
this.dbStatus.setText("Connected to Database");
} else {
this.dbStatus.setText("Not Connected to Database");
}
Year.getItems().addAll("2018","2017","2016","2015","2014","2013");
Type.getItems().addAll("Temperature","Pressure","UV","Humidity","Wind","Snow");
}
@FXML
private void loadData(ActionEvent event)throws SQLException{
try{
Connection connection = dbconn.getConnection();
this.data = FXCollections.observableArrayList();
ResultSet rs = connection.createStatement().executeQuery(sql);
while (rs.next()) {
this.data.add(new GeneralData(rs.getString(1),
rs.getString(2), rs.getString(3), rs.getString(4),
rs.getString(5), rs.getString(6), rs.getString(7),
rs.getString(8), rs.getString(9),rs.getString(10),
rs.getString(11), rs.getString(12)));
}
}
catch (SQLException e) {
System.err.println("Error " + e);
}
this.yearCol.setCellValueFactory(new PropertyValueFactory<GeneralData, String>("Year"));
this.monthCol.setCellValueFactory(new PropertyValueFactory<GeneralData, String>("Month"));
this.temperatureCol.setCellValueFactory(new PropertyValueFactory<GeneralData, String>("Temperature"));
this.windLowCol.setCellValueFactory(new PropertyValueFactory<GeneralData, String>("Wind_Lowest"));
this.windHighCol.setCellValueFactory(new PropertyValueFactory<GeneralData, String>("Wind_Highest"));
this.minUVICol.setCellValueFactory(new PropertyValueFactory<GeneralData, String>("MinUVI"));
this.maxUVICol.setCellValueFactory(new PropertyValueFactory<GeneralData, String>("MaxUVI"));
this.minAQICol.setCellValueFactory(new PropertyValueFactory<GeneralData, String>("MinAQI"));
this.maxAQICol.setCellValueFactory(new PropertyValueFactory<GeneralData, String>("MaxAQI"));
this.humidityCol.setCellValueFactory(new PropertyValueFactory<GeneralData, String>("Humidity"));
this.snowFallCol.setCellValueFactory(new PropertyValueFactory<GeneralData, String>("Snowfall"));
this.pressureCol.setCellValueFactory(new PropertyValueFactory<GeneralData, String>("Pressure"));
this.weatherTracerTable.setItems(null);
this.weatherTracerTable.setItems(data);
}
@FXML
private void search(ActionEvent event)throws SQLException {
int max = Integer.parseInt(maxField.getText());
int min = Integer.parseInt(miniField.getText());
String selectedYear = (String) Year.getSelectionModel().getSelectedItem();
String selectedType = (String) Type.getSelectionModel().getSelectedItem();
String fsql = "SELECT * FROM weather_tracer";
try {
if (!(Type.getSelectionModel().isEmpty()) && !(Year.getSelectionModel().isEmpty())) {
fsql = "SELECT * FROM weather_tracer where Year = " + selectedYear + " AND " + selectedType + " between " + min + " and " + max;
}
else if (!(Type.getSelectionModel().isEmpty())) {
fsql = "SELECT * FROM weather_tracer where " + selectedType + " between " + min + " and " + max;
}
Connection connection = dbconn.getConnection();
this.data = FXCollections.observableArrayList();
ResultSet rs = connection.createStatement().executeQuery(fsql);
while (rs.next()) {
this.data.add(new GeneralData(rs.getString(1),rs.getString(2), rs.getString(3), rs.getString(4), rs.getString(5), rs.getString(6), rs.getString(7), rs.getString(8), rs.getString(9),rs.getString(10), rs.getString(11), rs.getString(12)));
}
} catch (SQLException e) {
System.err.println("Error " + e);
}
this.yearCol.setCellValueFactory(new PropertyValueFactory<GeneralData, String>("Year"));
this.monthCol.setCellValueFactory(new PropertyValueFactory<GeneralData, String>("Month"));
this.temperatureCol.setCellValueFactory(new PropertyValueFactory<GeneralData, String>("Temperature"));
this.windLowCol.setCellValueFactory(new PropertyValueFactory<GeneralData, String>("Wind_Lowest"));
this.windHighCol.setCellValueFactory(new PropertyValueFactory<GeneralData, String>("Wind_Highest"));
this.minUVICol.setCellValueFactory(new PropertyValueFactory<GeneralData, String>("MinUVI"));
this.maxUVICol.setCellValueFactory(new PropertyValueFactory<GeneralData, String>("MaxUVI"));
this.minAQICol.setCellValueFactory(new PropertyValueFactory<GeneralData, String>("MinAQI"));
this.maxAQICol.setCellValueFactory(new PropertyValueFactory<GeneralData, String>("MaxAQI"));
this.humidityCol.setCellValueFactory(new PropertyValueFactory<GeneralData, String>("Humidity"));
this.snowFallCol.setCellValueFactory(new PropertyValueFactory<GeneralData, String>("Snowfall"));
this.pressureCol.setCellValueFactory(new PropertyValueFactory<GeneralData, String>("Pressure"));
this.weatherTracerTable.setItems(null);
this.weatherTracerTable.setItems(this.data);
}
}
向我的教授展示了演示之后。他告诉我，我犯了一些错误，因为我将所有数据合并为一个关系。我需要将其分为不同的小关系。现在，我有7个关系。如空气质量，湿度关系，降雪关系等...
我试图对上面列出的任何一种关系使用NATURAL JOIN并将其显示在表格视图中。但是我很难做到这一点，因为一旦声明了tableview，我就需要定义类型，之后便无法更改类型。有什么办法可以解决吗？