某大公司的面试题寻答案

[txgaozhao]

Q1.有一个学生表student，字段分别有自增主键id，学生名称name，分数score，记录时间rowdate
1）用一条语句，把及格（score>60）的记录的score改成1，把不及格的score都改成0，注意只能用一条语句
2）把学生名字重复的记录删除掉，每个名字只保留一条记录
Q2.
public myclass
{
public static int num=1;
public static myclass()
{
Console.WriteLine(++num);
}
public myclass()
{
Console.WriteLine(++num);
}
}

myclass a=new myclass();
myclass b=new myclass();
结果输出什么？

[amandag]

未测试..
Q1
1)
update student
set score = floor (score / 60)
2)
要看表的数据有多少，重复的数据有多少，解决方案不同
Q2
2
3
4

[鸭梨山大帝]

Q1:
1.

Update s set s.score = case when s1.score > 60 then 1 else 0 end
from Student s
inner join Student s1 on s1.id = s.id

2.

Delete student
where id not in 
(
select max(id) from student group by name
)

Q2:
执行步骤:
==> myclass a=new myclass();
==> num =1
==> public static myclass() ++num num = 2; (writeLine)
==> public myclass() ++num num=3; (writeLine)
==> myclass b=new myclass();
==> public myclass() ++num; num=4; (writeLine)

Result:
2
3
4

[鸭梨山大帝]

另外:
Q2,代码有问题.

public myclass ? ==> public class myclass

public static myclass() ? ==> static myclass()

[jianke917]

1.update student set score = floor (score / 60)
2.delete test where id not in (select max(id) from test group by name)
Q2.
2
3
4

[hsn820]

[Quote=引用 4 楼 huangwenquan123 的回复:]

静态构造函数可以有访问修饰符？
[/Quote]

对头，题目都有错误啦。。。public static myclass() 应该去掉public
结果是
2
3
4

[jason0019]

这个公司太大了
我已经受不鸟了

[xiao_run]

路过，看看!

[sxiaohui8709253]

[Quote=引用 6 楼 lost_painting 的回复:]
Q1:
1.

SQL code

Update s set s.score = case when s1.score > 60 then 1 else 0 end
from Student s
inner join Student s1 on s1.id = s.id



2.

SQL code

Delete student
where id not in ……
[/Quote]

顶起

[伴老思源]

update student set score = ( case when score > 60 then 1 else 0 end )

[vip__888]

像我上学时候的作业

[netajax1]

......................瞧瞧，瞅瞅

[nodbon]

有些难度

[tkscascor]

public static myclass() 构造函数, 可以使用static 定义的?

[ycproc]

汗 我只看看 我不说话

[Y_2716]

这也是大公司面试题..?

很像作业啊..

[teacher1998]

这个题目不错啊，记录下

[yjp2006]

[Quote=引用 6 楼 lost_painting 的回复:]
Q1:
1.

SQL code

Update s set s.score = case when s1.score > 60 then 1 else 0 end
from Student s
inner join Student s1 on s1.id = s.id


2.

SQL code

Delete student
where id not in ……
[/Quote]



支持。。。

[antony1029]

这也是大公司的题目？？

[zhangchunlin_ln]

1、update student set score=case when score>=60 then 1 when score < 60 then 0 end

2、delete test where id not in (select max(id) from test group by name)

[鸭梨山大帝]

6楼中我的回帖 Q1.1 写法有些啰嗦
inner join Student s1 on s1.id = s.id <== 这个完全没必要,呵呵