大家好,以下代码中select语句应该怎样改正呢?jspdev数据库中的Bk表里有属性bookID,且已存在054100117这一元组,但只有方法2才可以找出元组,但是这样必须事先知道属性值,如果我要以方法1操作,应该怎么改呢,谢谢~~
-------------------
方法1:
String temp = "054100117";
ResultSet rst = stmt.executeQuery("select * from jspdev..Bk where bookID=" + temp);
----------------------
方法2
ResultSet rst = stmt.executeQuery("select * from jspdev..Bk where bookID='054100117'");
-------------------
方法1:
String temp = "054100117";
ResultSet rst = stmt.executeQuery("select * from jspdev..Bk where bookID=" + temp);
----------------------
方法2
ResultSet rst = stmt.executeQuery("select * from jspdev..Bk where bookID='054100117'");
你可以把select语句这样写
"select * from jspdev..Bk where bookID = ?"
然后定义一个PreparedStatement变量,再在方法里利用PreparedStatement变量设置"问号"的值
具体就是这样:
String SBYTMP = select * from jspdev..Bk where bookID= ?"
private PreparedStatement ps;//方法有一个参数
public List findAll(String temp){
ps = conn.prepareStatement(SBYTMP);
ps.setString(1, temp);//这里的temp就是参数来的
rs = ps.executeQuery();
.....
.....
}
然后你可以调用这个函数得到你想要的结果