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Django: Set foreign key using integer?
...y is a particularly useful aspect of Django, one that everyone should know and use from time to time when appropriate.
caveat:
@RuneKaagaard points out that employee.type is not accurate afterwards in recent Django versions, even after calling employee.save() (it holds its old value). Using it wou...
Exclude .svn directories from grep [duplicate]
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If you use ack (a 'better grep') it will handle this automatically (and do a lot of other clever things too!). It's well worth checking out.
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What is cardinality in MySQL?
...ow.
Cardinality is a property which affects the ability to cluster, sort and search data. It is therefore an important measurement for the query planners in DBs, it is a heuristic which they can use to choose the best plans.
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Check if a value exists in ArrayList
...in order for this to work, you will need to properly override the equals() and hashCode() methods. If you are using Eclipse IDE, then you can have these methods generated by first opening the source file for your CurrentAccount object and the selecting Source > Generate hashCode() and equals()......
Scala constructor overload?
...ary Constructors in Scala must either call the primary constructor (as in landon9720's) answer, or another auxiliary constructor from the same class, as their first action. They cannot simply call the superclass's constructor explicitly or implicitly as they can in Java. This ensures that the primar...
Set the layout weight of a TextView programmatically
I'm trying to dynamically create TableRow objects and add them to a TableLayout .
The TableRow objects has 2 items, a TextView and a CheckBox . The TextView items need to have their layout weight set to 1 to push the CheckBox items to the far right.
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Loop through a date range with JavaScript
...dding one day causes the date to roll over to the next month if necessary, and without messing around with milliseconds. Daylight savings aren't an issue either.
var now = new Date();
var daysOfYear = [];
for (var d = new Date(2012, 0, 1); d <= now; d.setDate(d.getDate() + 1)) {
daysOfYear.p...
ConnectionTimeout versus SocketTimeout
...llisecond new data is received (assuming that you read the data block wise and the block is large enough)!
If only the incoming stream stalls for more than a millisecond you are running into a timeout.
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Adding 'serial' to existing column in Postgres
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Look at the following commands (especially the commented block).
DROP TABLE foo;
DROP TABLE bar;
CREATE TABLE foo (a int, b text);
CREATE TABLE bar (a serial, b text);
INSERT INTO foo (a, b) SELECT i, 'foo ' || i::text FROM generate_series(1, 5) i;...
Filtering Pandas DataFrames on dates
I have a Pandas DataFrame with a 'date' column. Now I need to filter out all rows in the DataFrame that have dates outside of the next two months. Essentially, I only need to retain the rows that are within the next two months.
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