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How to delete or add column in SQLITE?
...upports a limited subset of ALTER TABLE. The ALTER TABLE command in SQLite allows the user to rename a table or to add a new column to an existing table. It is not possible to rename a column, remove a column, or add or remove constraints from a table.
You can:
create new table as the one you ar...
What's the difference between a catalog and a schema in a relational database?
...l point of view :
The catalog is the place where--among other things--all of the various schemas (external, conceptual, internal) and all of the corresponding mappings (external/conceptual, conceptual/internal) are kept.
In other words, the catalog contains detailed information (sometimes...
CSS force image resize and keep aspect ratio
...ht:95px;
width: auto;
height: auto;
}
<p>This image is originally 400x400 pixels, but should get resized by the CSS:</p>
<img width="400" height="400" src="http://i.stack.imgur.com/aEEkn.png">
This will make image shrink if it's too big for specified area (as downsi...
Python - Get path of root project structure
...to prevent directories with a common name, such as string, from unintentionally hiding valid modules that occur later on the module search path. In the simplest case, __init__.py can just be an empty file, but it can also execute initialization code for the package or set the __all__ variable, descr...
What's the difference between SortedList and SortedDictionary?
...<TKey,TValue> ? Are there any circumstances where you would specifically use one and not the other?
7 Answers
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Advantages of stateless programming?
I've recently been learning about functional programming (specifically Haskell, but I've gone through tutorials on Lisp and Erlang as well). While I found the concepts very enlightening, I still don't see the practical side of the "no side effects" concept. What are the practical advantages of it? ...
How to access route, post, get etc. parameters in Zend Framework 2
...gt;fromFiles('paramname'); // From file being uploaded
Default values
All of these methods also support default values that will be returned if no parameter with the given name is found.
Example:
$orderBy = $this->params()->fromQuery('orderby', 'name');
When visiting http://example.com/?...
Regex for numbers only
I haven't used regular expressions at all, so I'm having difficulty troubleshooting. I want the regex to match only when the contained string is all numbers; but with the two examples below it is matching a string that contains all numbers plus an equals sign like "1234=4321". I'm sure there's a way...
How important is the order of columns in indexes?
... 3, the optimizer wouldn't even use the index, because it's not helpful at all in narrowing down the result sets. Anytime you're in a query, narrowing down the number of results to deal with before the next step means better performance.
Since the index is also stored this way, there's no backtrac...
Why is “except: pass” a bad programming practice?
...y to avoid passing in except blocks. Unless explicitly desired, this is usually not a good sign.
But let’s go into detail:
Don’t catch any error
When using a try block, you usually do this because you know that there is a chance of an exception being thrown. As such, you also already have an...