Pots
Time Limit: 1000MS
Memory Limit: 65536K
Total Submissions: 10071
Accepted: 4237
Special Judge
Description
You are given two pots, having the volume of A an...
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其他好文 时间:
2014-10-05 17:52:28
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193
本文通过实例介绍GROUP BY子句的使用方法。
1 准备测试数据
新建数据表tb_Student并插入下图所示的测试数据。
图1 数据表tb_Student的数据
2 使用GROUP BY子句进行分组
问题1
要求
按照班级ID对学生进行分组,并查询出每个班级的学生数,学生的最大年龄,最小年龄,年龄总和及年龄平均等信息。
解答
SELECT s.class_id...
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其他好文 时间:
2014-09-28 18:53:35
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267
PotsTime Limit:1000MSMemory Limit:65536KTotal Submissions:10042Accepted:4221Special JudgeDescriptionYou are given two pots, having the volume ofAandBl...
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其他好文 时间:
2014-09-25 14:18:29
阅读次数:
236
DescriptionConsider equations having the following form:a1x13+ a2x23+ a3x33+ a4x43+ a5x53=0The coefficients are given integers from the interval [-50,...
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其他好文 时间:
2014-09-24 22:22:47
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298
DescriptionConsider equations having the following form:a*x1^2+b*x2^2+c*x3^2+d*x4^2=0a, b, c, d are integers from the interval [-50,50] and any of the...
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其他好文 时间:
2014-09-24 20:58:47
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300
一条简单的查询sql格式如下: SELECT ... FROM .... [WHERE ...] --过滤单行 [GROUP BY ... [HAVING ...]]--GROUP BY对前面where条件过滤后的结果进行分组,HAVING过滤行组 [ORDER BY ...]--对结...
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数据库 时间:
2014-09-24 10:48:26
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239
A non-inclusive cache system includes an external cache and a plurality of on-chip caches each having a set of tags associated therewith, with at leas...
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其他好文 时间:
2014-09-22 16:03:22
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220
A multiprocessor computer system is provided having a multiplicity of sub-systems and a main memory coupled to a system controller. An interconnect mo...
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其他好文 时间:
2014-09-22 02:05:02
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349
A multiprocessing system having a plurality of processing nodes interconnected by an interconnect network. To optimize performance during spin-lock op...
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移动开发 时间:
2014-09-22 00:56:21
阅读次数:
394
where,group by,having重新详解 where的用法: where与in的配合使用,in(值1,值2,。。。)表示结果在值1,值2,。。。其中任何一个。 聚合函数和group by的用法: 聚合函数:在有聚合函数的select 字句中,出现其他的列名是没有意义的...
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数据库 时间:
2014-09-13 10:31:44
阅读次数:
251