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MySQL Query GROUP BY day / month / year

...ecord_date), MONTH(record_date) Check out the date and time functions in MySQL. share | improve this answer | follow | ...
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Foreign key constraints: When to use ON UPDATE and ON DELETE

I'm designing my database schema using MySQL Workbench, which is pretty cool because you can do diagrams and it converts them :P ...
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how to convert a string to date in mysql?

... As was told at MySQL Using a string column with date text as a date field, you can do SELECT STR_TO_DATE(yourdatefield, '%m/%d/%Y') FROM yourtable You can also handle these date strings in WHERE clauses. For example SELECT whatever...
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How to change the default GCC compiler in Ubuntu?

... @thang also called cc: root@host:/root# update-alternatives --get-selections | grep '/usr/bin/gcc' cc auto /usr/bin/gcc – jopasserat Aug 13 '16 at 15:26 ...
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mysql - how many columns is too many?

...tables with many rows, modifying the indexes can take a very long time, as MySQL needs to rebuild all of the indexes in the table. Having the indexes split over several table could make that faster. Depending on your queries and column types, MySQL could be writing temporary tables (used in more co...
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In Java, what is the best way to determine the size of an object?

... Pattern.normalizedPattern (object) 44 4 Node Pattern.root (object) 48 4 Node Pattern.matchRoot (object) 52 4 int[] Pattern.buffer null 56 4 Map Pattern.namedGroups null ...
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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...
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Importing modules from parent folder

... ├── __init__.py └── life.py I call the . the root folder, and in my case it is located in C:\tmp\test_imports. Steps 1) Add a setup.py to the root folder The contents of the setup.py can be simply from setuptools import setup, find_packages setup(name='myproject', ...
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How do I query between two dates using MySQL?

... DATE() is a MySQL function that extracts only the date part of a date or date/time expression SELECT * FROM table_name WHERE DATE(date_field) BETWEEN '2016-12-01' AND '2016-12-10'; ...
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How do I find which transaction is causing a “Waiting for table metadata lock” state?

...ransactions waiting for locks: SELECT TRX_ID, TRX_REQUESTED_LOCK_ID, TRX_MYSQL_THREAD_ID, TRX_QUERY FROM INNODB_TRX WHERE TRX_STATE = 'LOCK WAIT'; Reference - MySQL Troubleshooting: What To Do When Queries Don't Work, Chapter 6 - Page 96. ...