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MySQL order by before group by
...pand on my comments about using a subquery to accurate return this data.
MySQL does not force you to GROUP BY every column that you include in the SELECT list. As a result, if you only GROUP BY one column but return 10 columns in total, there is no guarantee that the other column values which bel...
What's faster, SELECT DISTINCT or GROUP BY in MySQL?
...doesn't have to sort the output, and GROUP BY by default does. However, in MySQL even a DISTINCT+ORDER BY might still be faster than a GROUP BY due to the extra hints for the optimizer as explained by SquareCog.
– rustyx
Jan 25 '15 at 15:03
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how to customize `show processlist` in mysql?
...any way you like.
The INFORMATION_SCHEMA.PROCESSLIST table was added in MySQL 5.1.7. You can find out which version you're using with:
SELECT VERSION()
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搭建高可用mongodb集群（二）—— 副本集 - 大数据 & AI - 清泛网 - 专注C/...
...切换连接？目前需要手工切换。
主节点的读写压力过大如何解决？
从节点每个上面的数据都是对数据库全量拷贝，从节点压力会不会过大？
数据压力大到机器支撑不了的时候能否做到自动扩展？
这篇文章看完这些问题就...
Rank function in MySQL
...NSI standard SQL query for my requirement. Please help me to convert it to MySQL .
11 Answers
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MySQL select where column is not empty
In MySQL, can I select columns only where something exists?
13 Answers
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MySQL: Set user variable from result of query
Is it possible to set an user variable based on the result of a query in MySQL?
4 Answers
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Change limit for “Mysql Row size too large”
... You may want to take a look at this article which explains a lot
about MySQL row sizes. It's important to note that even if you use
TEXT or BLOB fields, your row size could still be over 8K (limit for
InnoDB) because it stores the first 768 bytes for each field inline in
the page.
The...
SQL Server equivalent to MySQL enum data type?
Does SQL Server 2008 have a a data-type like MySQL's enum ?
5 Answers
5
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Convert Unix timestamp into human readable date using MySQL
Is there a MySQL function which can be used to convert a Unix timestamp into a human readable date? I have one field where I save Unix times and now I want to add another field for human readable dates.
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