大约有 19,000 项符合查询结果（耗时：0.0205秒） [XML]
Get records with max value for each group of grouped SQL results
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There's a super-simple way to do this in mysql:
select *
from (select * from mytable order by `Group`, age desc, Person) x
group by `Group`
This works because in mysql you're allowed to not aggregate non-group-by columns, in which case mysql just returns the first...
从Code Review 谈如何做技术 - 更多技术 - 清泛网 - 专注C/C++及内核技术
从Code Review 谈如何做技术这两天，在微博上表达了一下Code Review的重要性。因为翻看了阿里内部的Review Board上的记录，从上面发现Code Review做得好的是一些比...这两天，在微博上表达了一下Code Review的重要性。因为翻看了阿里内部...
How can I include a YAML file inside another?
...custom constructors (such as !include) to the YAML loader. I've included a root directory that can be set so that this solution supports relative and absolute file references.
Class-Based Solution
Here is a class-based solution, that avoids the global root variable of my original response.
See th...
Difference between VARCHAR and TEXT in MySQL [duplicate]
When we create a table in MySQL with a VARCHAR column, we have to set the length for it. But for TEXT type we don't have to provide the length.
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How to get UTF-8 working in Java webapps?
...s" those characters.
To get UTF-8 working under Java+Tomcat+Linux/Windows+Mysql requires the following:
Configuring Tomcat's server.xml
It's necessary to configure that the connector uses UTF-8 to encode url (GET request) parameters:
<Connector port="8080" maxHttpHeaderSize="8192"
maxThreads...
MySQL Update Inner Join tables query
I have no idea what the problem is. Using MySQL 5.0 I get a compile error when attempting to run the following MySQL update query:
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How to Get True Size of MySQL Database?
I would like to know how much space does my MySQL database use, in order to select a web host.
I found the command SHOW TABLE STATUS LIKE 'table_name' so when I do the query, I get something like this:
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MySQL load NULL values from CSV data
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MySQL manual says:
When reading data with LOAD DATA
INFILE, empty or missing columns are
updated with ''. If you want a NULL
value in a column, you should use \N
in the data file. The literal word
“NULL” ma...
Discuz! X3 论坛标题字数突破80的限制 - 更多技术 - 清泛网 - 专注C/C++及内核技术
... _forum_rsscache, _forum_thread 这三张表）：
下面详细介绍如何修改：
一、数据库修改，修改数据库标题字段的长度为255字符：运行下面的sql语句：
（注意修改你的表的前缀，还有修改前一定要备份！！！）
ALTER TABLE `pre_forum...
Error 1046 No database Selected, how to resolve?
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You need to tell MySQL which database to use:
USE database_name;
before you create a table.
In case the database does not exist, you need to create it as:
CREATE DATABASE database_name;
followed by:
USE database_name;
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