1、DISTINCT用法:
SELECT DISTINCT A.NAME , A.STUDENT_ID , A.SEX FROM TABLE STUDENT
这条SQL语句是从学生表里查询了姓名,学号,性别,但是DISTINCT的查询规则是只要有一个不同,就是符合条件的。
例: 源数据...
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数据库 时间:
2014-10-30 20:57:44
阅读次数:
249
Longest Ordered SubsequenceDescriptionA numeric sequence of ai is ordered if a1 File Name: poj2533.cpp 3 > Author: Enumz 4 > Mail: 369372123@...
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其他好文 时间:
2014-10-30 16:56:36
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164
Given a stringSand a stringT, count the number of distinct subsequences ofTinS.A subsequence of a string is a new string which is formed from the orig...
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其他好文 时间:
2014-10-30 07:06:13
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171
You are climbing a stair case. It takes n steps to reach to the top.
Each time you can either climb 1 or 2 steps. In how many distinct ways can you climb to the top?
每一次你可以爬一层或者两层,计算爬n层你...
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其他好文 时间:
2014-10-30 00:24:42
阅读次数:
202
You are climbing a stair case. It takes n steps to reach to the top.
Each time you can either climb 1 or 2 steps. In how many distinct ways can you climb to the top?
简单递推
class Solution {
pub...
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其他好文 时间:
2014-10-29 22:21:11
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175
Common Subsequence
Time Limit: 1000MS
Memory Limit: 10000K
Total Submissions: 39128
Accepted: 15770
Description
A subsequence of a given sequence is the given seque...
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其他好文 时间:
2014-10-29 17:06:06
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261
You are climbing a stair case. It takesnsteps to reach to the top.Each time you can either climb 1 or 2 steps. In how many distinct ways can you climb...
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其他好文 时间:
2014-10-29 12:48:28
阅读次数:
170
名词Cardinality: 优化器在计算成本的时候,需要从统计信息中取得数据,然后去估计每一步操作所涉及的行数,叫做Cardinality。 比如,一张表T有1000行数据,列COL1上没有直方图,没有空值,并且不重复的值(distinct value)有500个。那么,在使用条件“WHERE.....
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其他好文 时间:
2014-10-29 10:27:54
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117
H -LISTime Limit:2000MSMemory Limit:65536KB64bit IO Format:%I64d & %I64uSubmitStatusDescriptionA numeric sequence ofaiis ordered ifa1<a2< ... <aN. Let...
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其他好文 时间:
2014-10-28 23:49:45
阅读次数:
261
The n-queens puzzle is the problem of placing n queens on an n×n chessboard such that no two queens attack each other.
Given an integer n, return all distinct solutions to the n-queens puzzle.
...
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其他好文 时间:
2014-10-28 20:03:53
阅读次数:
245