我的程序中出現錯誤

Question

C:\Users\PRAVEEN\Desktop>javac afterlogin.java 
afterlogin.java:20: cannot find symbol 
symbol : class Connection 
location: class afterlogin 
         Connection z=DriverManager.getConnection("jdbc:mysql://localhost:3306/db","root","root"); 
         ^
afterlogin.java:20: cannot find symbol 
symbol : variable DriverManager 
location: class afterlogin 
         Connection z=DriverManager.getConnection("jdbc:mysql://localhost:3306/db","root","root"); 
            ^
afterlogin.java:21: cannot find symbol 
symbol : class PreparedStatement 
location: class afterlogin 
         PreparedStatement ps=z.PreparedStatement("insert into reg(fn,ln,pwd,email,mob)values(?????)"); 

Answer 1

您應該在afterLogin.java上導入以解決編譯過程中遇到的這些錯誤。以下是您需要添加的導入內容。

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

您發佈的編譯錯誤也不完整。我建議你，如果你不熟悉JDBC的編程，請遵循一個特定的教程。有大量的文章可以指導你完成這個過程。