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Python: Tuples/dictionaries as keys, select, sort
...d like to organize them in a data structure in Python that allows for easy selection and sorting. My idea was to put them into a dictionary with tuples as keys, e.g.,
...
Could not instantiate class named MKMapView
... project to bring the project settings. Under Targets, click your project, select from the upper toolbar "Build Phases". Under "Link binary With Libraries" tab, you will see the list of frameworks included in your project. Click the "+" button and add MapKit library from the shown list to your proje...
Difference between 'struct' and 'typedef struct' in C++?
...t constructor,
and a conversion operator that
converts a foo object to char const *.
The expression
p = foo();
in main should construct a foo object
and apply the conversion operator. The
subsequent output statement
cout << p << '\n';
should display class foo, but...
When to use a View instead of a Table?
...
Oh there are many differences you will need to consider
Views for selection:
Views provide abstraction over tables. You can add/remove fields easily in a view without modifying your underlying schema
Views can model complex joins easily.
Views can hide database-specific stuff from you. E....
How to check if a stored procedure exists before creating it
...a query.
Just copy everything after AS:
BEGIN
DECLARE @myvar INT
SELECT *
FROM mytable
WHERE @myvar ...
END
This code does exactly same things a stored proc would do, but is not stored on the database side.
That's much like what is called anonymous procedure in PL/SQL.
Up...
How to get database structure in MySQL via query
...CHEMA.TABLES table. It contains metadata about all your tables.
Example:
SELECT * FROM `INFORMATION_SCHEMA`.`TABLES`
WHERE TABLE_NAME LIKE 'table1'
The advantage of this over other methods is that you can easily use queries like the one above as subqueries in your other queries.
...
Show an image preview before upload
... code snippet in the HTML example below filters out images from the user's selection and renders selected files into multiple thumbnail previews:
function handleFileSelect(evt) {
var files = evt.target.files;
// Loop through the FileList and render image files as thumbnails.
fo...
Ignoring time zones altogether in Rails and PostgreSQL
...n parameter before being displayed to the client.
Example (in psql):
db=# SELECT timestamptz '2012-03-05 20:00+03';
timestamptz
------------------------
2012-03-05 18:00:00+01
What happened here?
I chose an arbitrary time zone offset +3 for the input literal. To Postgres, this is just one o...
How can I print literal curly-brace characters in python string and also use .format on it?
...ying to format a small JSON for some purposes, like this: '{"all": false, "selected": "{}"}'.format(data) to get something like {"all": false, "selected": "1,2"}
It's pretty common that the "escaping braces" issue comes up when dealing with JSON.
I suggest doing this:
import json
data = "1,2"
my...
How do I directly modify a Google Chrome Extension File? (.CRX)
... remove the _metadata folder.
From chrome://extensions in Developer mode select Load unpacked extension... and select your copied extension folder, if it contains a subfolder this is named by the version, select this version folder where there is a manifest file, this file is necessary for Chrome....