JAVA+JAVAFX实现的SQLServer简易数据库操作界面

package sample;

import javafx.application.Application;
import javafx.collections.FXCollections;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.geometry.Insets;
import javafx.geometry.Pos;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.ChoiceBox;
import javafx.scene.control.Label;
import javafx.scene.control.TextField;
import javafx.scene.layout.GridPane;
import javafx.scene.layout.HBox;
import javafx.scene.text.Font;
import javafx.scene.text.FontWeight;
import javafx.scene.text.Text;
import javafx.stage.Stage;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;

public class Main extends Application {
    @Override
    public void start(Stage primaryStage) throws Exception{
        try {
            GridPane grid = new GridPane();

            grid.setAlignment(Pos.CENTER); //对齐方式(居中)
            grid.setHgap(15); //水平距离
            grid.setVgap(15); //垂直距离
            grid.setAlignment(Pos.TOP_CENTER);
            grid.setPadding(new Insets(25,25,25,25)); //设置内边距
            //数据库名称
            Label database = new Label("数据库名称：");
            grid.add(database, 0, 0);
            TextField databaseTextField = new TextField();
            grid.add(databaseTextField, 1, 0);
            //操作符
            Label op = new Label("操作符：");
            grid.add(op, 0, 2);
            //下拉框
            ChoiceBox cb = new ChoiceBox(FXCollections.observableArrayList("Create", "Select", "Insert", "Delete", "Update"));
            grid.add(cb, 1, 2);
            //操作表
            Label table = new Label("操作表：");
            grid.add(table, 0, 3);
            TextField tableTextField = new TextField();
            grid.add(tableTextField, 1, 3);
            //操作数
            Label number = new Label("操作数：");
            grid.add(number, 0, 4);
            TextField numberTextField = new TextField();
            grid.add(numberTextField, 1, 4);
            //操作条件
            Label where = new Label("操作条件：");
            grid.add(where, 0, 5);
            TextField whereTextField = new TextField();