//创建语句容器
Statement st=conn.createStatement();
//执行sql语句
ResultSet rs=st.executeQuery("select * from admin_info where name='"+t+"' and pwd='"+b+"'");
//遍历结果集
while(rs.next()){
System.out.print(rs.getString("id"));
System.out.print(rs.getString("name"));
System.out.print(rs.getString("pwd "));
}
这种方法不安全有sql注入的安全隐患
解决sql注入的方法,利用PreparedStatement:预处理语句容器
PreparedStatement允许在sql语句使用占位符?
PreparedStatement的优点:
1.解决sql注入
2.提高程序可读性和可维护性
3.执行效率高
String sql="select * from admin_info where name=? and pwd=?";
PreparedStatement pt=conn.prepareStatement(sql);
//执行sql语句之前需要给需要给参数赋值
pt.setString(1, t);
pt.setString(2, b);
//执行sql语句
ResultSet rs =pt.executeQuery();