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Adding 'serial' to existing column in Postgres
I have a small table (~30 rows) in my Postgres 9.0 database with an integer ID field (the primary key) which currently contains unique sequential integers starting at 1, but which was not created using the 'serial' keyword.
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JavaScript exponents
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answered Nov 18 '15 at 20:04
Salvador DaliSalvador Dali
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Pandas aggregate count distinct
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How about either of:
>>> df
date duration user_id
0 2013-04-01 30 0001
1 2013-04-01 15 0001
2 2013-04-01 20 0002
3 2013-04-02 15 0002
4 2013-04-02 30 0002
>>> df.groupby("date").agg({"duration": np.sum, "user_id...
Are there console commands to look at whats in the queue and to clear the queue in Sidekiq?
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90
I haven't ever used Sidekiq, so it's possible that there are methods just for viewing the queued...
Insert image after each list item
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330
The easier way to do it is just:
ul li:after {
content: url('../images/small_triangle.png')...
How to get an enum which is created in attrs.xml in code
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101
There does not seem to be an automated way to get a Java enum from an attribute enum - in Java ...
What is the formal difference in Scala between braces and parentheses, and when should they be used?
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370
I tried once to write about this, but I gave up in the end, as the rules are somewhat diffuse. B...
Storing R.drawable IDs in XML array
... within your /res/values folder that looks like this:
<?xml version="1.0" encoding="utf-8"?>
<resources>
<integer-array name="random_imgs">
<item>@drawable/car_01</item>
<item>@drawable/balloon_random_02</item>
<item>@draw...
What is the maximum number of characters that nvarchar(MAX) will hold?
...re detailed numbers, you should be able to store
(2 ^ 31 - 1 - 2) / 2 = 1'073'741'822 double-byte characters
1 billion, 73 million, 741 thousand and 822 characters to be precise
in your NVARCHAR(MAX) column (unfortunately, that last half character is wasted...)
Update: as @MartinMulder pointed ...
Efficiently checking if arbitrary object is NaN in Python / numpy / pandas?
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170
pandas.isnull() (also pd.isna(), in newer versions) checks for missing values in both numeric an...