作者:iamlaosong
多表连接查询中最常用的事内连接,内连接中最常用的是等值连接,即在连接条件中使用等于号(=)运算符比较被连接列的列值,其查询结果中列出被连接表中的所有列,包括其中的重复列。例如:
select * from tb_evt_mail_clct a, tb_evt_dlv c
where a.clct_date between to_date('2015-6-11'...
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其他好文 时间:
2015-06-15 18:47:19
阅读次数:
150
mysql> SELECT concat('KILL ',id,';') FROM information_schema.processlist WHERE user='root';+------------------------+| concat('KILL ',id,';') |+------...
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数据库 时间:
2015-06-15 18:12:46
阅读次数:
173
Method 1:From book select greatest(@found := -1, user_id) as user_id, 'user' as which_tbl from user where user_id = 1union allselect user_id as user.....
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数据库 时间:
2015-06-15 18:12:43
阅读次数:
130
Description:Given a sorted array and a target value, return the index if the target is found. If not, return the index where it would be if it were in...
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其他好文 时间:
2015-06-15 16:14:20
阅读次数:
106
今天遇到一个问题,想要删掉一个表中的某列的唯一约束,google了一下,搜出来许许多多,找到能用的,记下来总结如下。命令如下select constname, tabname, colname, colseq from syscat.keycoluse where TABNAME='TableNam...
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数据库 时间:
2015-06-15 14:29:48
阅读次数:
114
Given a sorted integer array where the range of elements are [lower, upper] inclusive, return its missing ranges.For example, given [0, 1, 3, 50, 75], lower = 0 and upper = 99, return ["2", "4->49", "...
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其他好文 时间:
2015-06-15 13:09:51
阅读次数:
153
查看被锁表:select request_session_id spid,OBJECT_NAME(resource_associated_entity_id) tableName from sys.dm_tran_locks where resource_type='OBJECT's...
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数据库 时间:
2015-06-15 13:05:54
阅读次数:
144
Given n non-negative integers a1, a2, ..., an, where each represents a point at coordinate (i, ai). n vertical lines are drawn such that the two endpoints of line i is at (i, ai) and (i, 0). Find two ...
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其他好文 时间:
2015-06-15 09:36:47
阅读次数:
78
SQL> select * from v$version where rownum=1;
BANNER
--------------------------------------------------------------------------------
Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - Prod...
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其他好文 时间:
2015-06-15 09:23:27
阅读次数:
170
Given a string s and a dictionary of words dict, add spaces in s to construct a sentence where each word is a valid dictionary word.Return all such po...
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其他好文 时间:
2015-06-15 06:54:37
阅读次数:
210