从代码创建 JAVA 数据库。语句不会执行并创建表？

Question

我不确定为什么我的程序没有创建表格，但我还需要一些关于如何在表格创建后用这样的代码填充表格的想法？我还需要在这个数据库中再添加两个表。

这是我得到的错误：

java.sql.SQLSyntaxErrorException: Table/View 'PIZZASIZE' does not exist.
Caused by: ERROR 42X05: Table/View 'PIZZASIZE' does not exist.
Caused by: java.lang.RuntimeException: Exception in Application start method
Caused by: javafx.fxml.LoadException: file:/C:/Users/Allie/Documents/NetBeansProjects/Pizzeria_AllieBeckman/dist/run1674141987/Pizzeria_AllieBeckman.jar!/pizzeria_alliebeckman/FXMLDocument.fxml

这是应该创建表的代码：

        // connect to the derby URL using the given username and password
        connect = DriverManager.getConnection("jdbc:derby://localhost:1527/pizzeria;create=true", connectProps);
        // current url for pre created database "jdbc:derby://localhost:1527/pizza"
        // if connection is successful print that it succeeded.
        System.out.println("database created");

        stmt = connect.createStatement();

        String sqlCreate = "CREATE TABLE PIZZASIZE "
            + "(id int NOT NULL, "
            + "size char(20) NOT NULL, "
            + "PRIMARY KEY (id))";

        stmt.execute(sqlCreate); 

Answer 1

根据您使用的 IDE，您可以在控制台中手动创建表，而无需费心编写代码。以下是一些关于如何从表格中获取信息的示例。

Connection conn = CreatingDerbyDJB.dbConnection();

            try{
                String query = "INSERT INTO  Items (Name,Color,ItemName,SchoolName, Description) VALUES(?,?,?,?, ?)";
                PreparedStatement pstmt = conn.prepareStatement(query);


                pstmt.execute();
                conn.close();
              }catch(Exception e)
            {
                  e.printStackTrace();
            }       }

以下是 Connection 类的外观： 主包;

import java.sql.Connection;
import java.sql.DriverManager;

import javax.swing.JOptionPane;

public class CreatingDerbyDJB 
{
    public static final String DRIVER = "org.apache.derby.jdbc.EmbeddedDriver";
    public static final String JDBC_URL  = "jdbc:derby:LostAndFoundDB";
    public static Connection dbConnection()
    {
        try
        {
            Class.forName(DRIVER).newInstance();
            Connection c = DriverManager.getConnection(JDBC_URL);
            return c;
        }catch(Exception e)
        {
            JOptionPane.showMessageDialog(null, e);
            return null;
        }
    }
}

如果这对您有帮助，请批准此答案，如果没有意义，我很乐意解释。 :)