[转载] 朋友传给我的INTERVIEW问题2...SQL - 未名空间MITBBS历史存档

国际科技财经博客移民网络热点娱乐民生时事公众号

Redian新闻

>未名空间

>Database - 数据库

[转载] 朋友传给我的INTERVIEW问题2...SQL

[转载] 朋友传给我的INTERVIEW问题2...SQL# Database - 数据库

n*g2003-01-28 08:01

1 楼

【以下文字转载自 JobHunting 讨论区,原文如下】
发信人: njying (嘟嘟), 信区: JobHunting
标题: 朋友传给我的INTERVIEW问题2...SQL
发信站: The unknown SPACE (Tue Jan 28 18:44:49 2003) WWW-POST
1. There is a table 'T' with order ids ('oi') and customer ids ('ci'). Each
order only belongs to a single customer and each customer may have multiple
orders. How do you find how many orders each customer has? Please provide
the SQL.
2. Users report that the server has become non-responsive. What are the
possible explanations, and how do

a*i2003-01-28 08:01

2 楼

SELECT COUNT(oi) FROM T GROUP BY ci ?
That depends on what he means by "non-responsive" bah.
Isolation level.
Not sure why they might occur in a simple situation. Never had one in my
life.:)

【在 n****g 的大作中提到】

: 【以下文字转载自 JobHunting 讨论区,原文如下】
: 发信人: njying (嘟嘟), 信区: JobHunting
: 标题: 朋友传给我的INTERVIEW问题2...SQL
: 发信站: The unknown SPACE (Tue Jan 28 18:44:49 2003) WWW-POST
: 1. There is a table 'T' with order ids ('oi') and customer ids ('ci'). Each
: order only belongs to a single customer and each customer may have multiple
: orders. How do you find how many orders each customer has? Please provide
: the SQL.
: 2. Users report that the server has become non-responsive. What are the
: possible explanations, and how do

g*o2003-01-28 08:01

3 楼

Each
multiple
provide
in
A
normally
simple
two transactions are waiting for each other when they try to act to the same
data object since DBMA will put a lock on the data object before it was
accessed by any transactions

【在 a*****i 的大作中提到】

:
: SELECT COUNT(oi) FROM T GROUP BY ci ?
: That depends on what he means by "non-responsive" bah.
: Isolation level.
: Not sure why they might occur in a simple situation. Never had one in my
: life.:)