Java执行SQL的insert语句

public class JDBC_2 {
public static void main(String[] args) {
try{
Class.forName("com.mysql.jdbc.Driver");
String url = "jdbc:mysql://localhost:3306/xskc";
String user = "root";
String pwd = "mch0dmin";
java.sql.Connection con = DriverManager.getConnection(url, user, pwd);
//java.sql.Statement stmt = con.createStatement();
Statement stmt = null;
String sql = "insert into student values('95005', '张三', '男', 50, 'DC')";
//String sql = "select sno from student";
stmt.executeQuery(sql);

        如果执行的是注释中的select语句，就不会报错，按时执行insert语句，就出现问题，请大牛帮帮忙！谢谢！