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How to Test a Concern in Rails
...t I have a Personable concern in my Rails 4 application which has a full_name method, how would I go about testing this using RSpec?
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MongoDB - Update objects in a document's array (nested updating)
...reak it into two parts. First, increment any document that has "items.item_name" equal to "my_item_two". For this you'll have to use the positional "$" operator. Something like:
db.bar.update( {user_id : 123456 , "items.item_name" : "my_item_two" } ,
{$inc : {"items.$.price" : ...
postgresql COUNT(DISTINCT …) very slow
...
You can use this:
SELECT COUNT(*) FROM (SELECT DISTINCT column_name FROM table_name) AS temp;
This is much faster than:
COUNT(DISTINCT column_name)
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Assign one struct to another in C
...ree() because they are automatic variables: en.wikipedia.org/wiki/Automatic_variable
– joshdoe
Jun 19 '12 at 16:32
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How to detect incoming calls, in an Android device?
...this:
Manifest:
<uses-permission android:name="android.permission.READ_PHONE_STATE" />
<uses-permission android:name="android.permission.PROCESS_OUTGOING_CALLS"/>
<!--This part is inside the application-->
<receiver android:name=".CallReceiver" >
<intent-fil...
How to form tuple column from two columns in Pandas
...rtable with zip. It comes in handy when dealing with column data.
df['new_col'] = list(zip(df.lat, df.long))
It's less complicated and faster than using apply or map. Something like np.dstack is twice as fast as zip, but wouldn't give you tuples.
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Renaming table in rails
...ion:
class RenameFoo < ActiveRecord::Migration
def self.up
rename_table :foo, :bar
end
def self.down
rename_table :bar, :foo
end
end
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How do I create a parameterized SQL query? Why Should I?
...= @Baz"
Using cn As New SqlConnection("Your connection string here"), _
cmd As New SqlCommand(sql, cn)
cmd.Parameters.Add("@Baz", SqlDbType.VarChar, 50).Value = Baz
Return cmd.ExecuteScalar().ToString()
End Using
End Function
Stored procedures are sometimes credit...
How to use Swift @autoclosure
...answered Jun 8 '14 at 5:28
eddie_ceddie_c
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Generate random numbers uniformly over an entire range
...t generate numbers uniformly (it depends on the range and the value of RAND_MAX), and is therefore discouraged.
C++11 and generation over a range
With C++11 multiple other options have risen. One of which fits your requirements, for generating a random number in a range, pretty nicely: std::uniform_...