Java：在数据库中创建表

Question

我一直在尝试在数据库中创建表。 该代码未显示任何错误且运行正常，但最后在数据库中未创建任何表。 请帮助。

public void createTable(){

    try {

    String host = "jdbc:derby://localhost:1537/fypDB";
    String uname = "test";
    String pword = "test";
    Connection con = DriverManager.getConnection( host, uname, pword );
    Statement stmt = con.createStatement();

   //username is valid variable from main class 
    String SQL = "CREATE TABLE "+username+" (classId VARCHAR(255), "+"PRIMARY KEY ( classId ))";
    stmt.executeUpdate( SQL );
    System.out.println(SQL);

    } catch (SQLException err){
        System.out.println(err.getMessage());
    }
}

Answer 1

这应该做

Class.forName("org.apache.derby.jdbc.ClientDriver");
Connection con = DriverManager.getConnection("jdbc:derby://localhost:1537/fypDB", 
                                                  "yourUsername", "ypurPassword");
Statement stmt = con.createStatement();
stmt.execute( SQL );

不要忘记将derbyclient.jar放在类路径中并关闭连接