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Align contents inside a div
...s to work in IE6, you need to make sure Standards Mode is on by using a suitable DOCTYPE.
If you really need to support IE5/Quirks Mode, which these days you shouldn't really, it is possible to combine the two different approaches to centering:
<div style="text-align: center">
<div st...
How can I select rows with most recent timestamp for each key value?
I have a table of sensor data. Each row has a sensor id, a timestamp, and other fields. I want to select a single row with latest timestamp for each sensor, including some of the other fields.
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Ship an application with a database
...re database from there. This is much quicker if the database has a lot of tables and other components. Upgrades are triggered by changing the database version number in the res/values/strings.xml file. Upgrades would then be accomplished by creating a new database externally, replacing the old dat...
Django dynamic model fields
...s based on Entity Attribute Value data model, essentially, it uses several tables to store dynamic attributes of objects. Great parts about this solution is that it:
uses several pure and simple Django models to represent dynamic fields, which makes it simple to understand and database-agnostic;
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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
...你的表的前缀，还有修改前一定要备份！！！）
ALTER TABLE `pre_forum_post` CHANGE `subject` `subject` varchar(255) NOT NULL;
ALTER TABLE `pre_forum_rsscache` CHANGE `subject` `subject` varchar(255) NOT NULL;
ALTER TABLE `pre_forum_thread` CHANGE `subject` `subject` varchar(255...
Run a single migration file
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Note that if you do this, it probably won't update the schema_migrations table, but it seems like that's what you want anyway.
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What does “hashable” mean in Python?
... data structures use the hash value internally.
All of Python’s immutable built-in objects are hashable, while no mutable containers (such as lists or dictionaries) are. Objects which are instances of user-defined classes are hashable by default; they all compare unequal, and their hash value...
SQL Switch/Case in 'where' clause
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I'd say this is an indicator of a flawed table structure. Perhaps the different location types should be separated in different tables, enabling you to do much richer querying and also avoid having superfluous columns around.
If you're unable to change the structur...
Remove characters except digits from string using Python?
...digs)
'1233344554552'
>>>
string.maketrans makes a translation table (a string of length 256) which in this case is the same as ''.join(chr(x) for x in range(256)) (just faster to make;-). .translate applies the translation table (which here is irrelevant since all essentially means iden...
Is gcc std::unordered_map implementation slow? If so - why?
...red_map, the g++ implementation will automatically rehash to a larger hash table, and this would be a big drag on performance. If I remember correctly, unordered_map defaults to (smallest prime larger than) 100.
I didn't have chrono on my system, so I timed with times().
template <typename TEST...