jsp 连接数据库时抛出异常!

来源:百度知道 编辑:UC知道 时间:2024/05/26 07:26:24
如题,在连接数据库并且获取数据库里面的值和用户输入的值进行比较时,抛出异常,代码如下:
rs=sql.executeQuery("SELECT c.customer_name, p.*, pr.address as producer_address, m.maintain_name, m.address as maintain_address, m.buy_time, m.maintain_time FROM customer as c, producer as pr, product as p, maintain as m WHERE c.product_id = m.product_id and c.product_id = p.product_id and p.producer_name = pr.producer_name;");
out.print("<Table Border>");
out.print("<TR>");
out.print("<TH width=50>"+"姓名");
out.print("<TH width=50>"+"产品型号");
out.print("<TH width=50>"+"生产厂家");
out.print("<TH width=50>"+"CPU");
out.print("<TH width=50>"+"主板");
out.print("<TH width=50>"+"硬盘");
out.print("<

编程 看都看晕了 我朋友学呢 他估计能看懂吧

祝你好运吧!

用户输入的值在SQL语句中,如果是String型'"+u+"'进行连接,其他的一般"+u+",就这样,而你的SQL语句一看就是错的,好好研究吧