从代码创建 JAVA 数据库。语句不会执行并创建 table？

Question

我不确定为什么我的程序没有创建 table，但我还需要一些关于如何在创建 table 后用这样的代码填充它的想法？我还需要向该数据库中添加两个 table。

这是我遇到的错误：

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 table:

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 table，而无需在代码中编写它。以下是一些如何从 table 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();
            }       }

连接 class 应该是这样的：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;
        }
    }
}

如果对您有帮助，请采纳此回答，如果有不明白的地方，我很乐意解释。 :)

从代码创建 JAVA 数据库。语句不会执行并创建 table？

Creating a JAVA database from code. Statement wont execute and create table?

java

sql

database

database-connection

derby