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How to slice an array in Bash
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There is also a convenient shortcut to get all elements of the array starting with specified index. For example "${A[@]:1}" would be the "tail" of the array, that is the array without its first element.
version=4.7.1
A=( ${version//\./ } )
echo "${A[@]}" # 4 7 1
B...
How to restore to a different database in sql server?
...mpCopy with the contents of your.bak.
Example (restores a backup of a db called 'creditline' to 'MyTempCopy';
RESTORE FILELISTONLY FROM DISK='e:\mssql\backup\creditline.bak'
>LogicalName
>--------------
>CreditLine
>CreditLine_log
RESTORE DATABASE MyTempCopy FROM DISK='e:\mssql\backu...
Access denied for user 'root'@'localhost' while attempting to grant privileges. How do I grant privi
... basics. Though of course, that doesn't mean I haven't missed something totally obvious. :-)
13 Answers
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Can you create nested WITH clauses for Common Table Expressions?
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Essentially the post means, that you can't do it, but it is not a big problem.
– peterh - Reinstate Monica
May 30 '17 at 14:40
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Rails 3 execute custom sql query without a model
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Maybe try this:
ActiveRecord::Base.establish_connection(...)
ActiveRecord::Base.connection.execute(...)
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How to check if a table exists in a given schema
... (like OIDs) gets lost in translation from the system catalogs - which actually carry all information.
System catalogs
Your question was:
How to check whether a table exists?
SELECT EXISTS (
SELECT FROM pg_catalog.pg_class c
JOIN pg_catalog.pg_namespace n ON n.oid = c.relnamespace
WHE...
Calculate the median of a billion numbers
...bably too late if this had been an interview, but never mind:
Machine 1 shall be called the "control machine", and for the sake of argument either it starts with all the data, and sends it in equal parcels to the other 99 machines, or else the data starts evenly distributed between the machines, an...
Is it safe to use -1 to set all bits to true?
...s one:
unsigned long a = ~0u;
It won't necessarily store a pattern with all bits 1 into a. But it will first create a pattern with all bits 1 in an unsigned int, and then assign it to a. What happens when unsigned long has more bits is that not all of those are 1.
And consider this one, which wi...
Simple way to encode a string according to a password?
... to do much work to implement a proper encryption scheme however. First of all, don’t re-invent the cryptography wheel, use a trusted cryptography library to handle this for you. For Python 3, that trusted library is cryptography.
I also recommend that encryption and decryption applies to bytes; ...
Generate random numbers with a given (numerical) distribution
...> choices(population, weights)
4
The optional keyword-only argument k allows one to request more than one sample at once. This is valuable because there's some preparatory work that random.choices has to do every time it's called, prior to generating any samples; by generating many samples at o...