查人人中国名人网roland app:关于数据库与java程序连接的问题
来源：百度文库 编辑：查人人中国名人网 时间：2024/04/28 18:18:27
我用access 做的数据库，连到我用java做的系统里，然后我希望把程序里的一个变量插入数据库里，但SQL语句那却有了问题
int punishmoney = (today.getDay()-rday.getDay())*1;
sqlStr = "insert into punishment(user_cardnumber,sum_account) values (?,punishmoney)";
int punishmoney = (today.getDay()-rday.getDay())*1;
sqlStr = "insert into punishment(user_cardnumber,sum_account) values (?,punishmoney)";
不能这样写，写到一条语句里punishmoney只是一个字符串，而不是变量
应该分开写
sqlStr = "insert into punishment(user_cardnumber,sum_account) values (?,"+punishmoney+")";
你这样写punishmoney就相当于一个字符串了
如果sum_account为数值型，就会出错了
这样写就可以了
int punishmoney = (today.getDay()-rday.getDay())*1;
sqlStr = "insert into punishment(user_cardnumber,sum_account) values (?," + new Integer(punishmoney).toString() + ")";