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Difference between filter and filter_by in SQLAlchemy
... filter on users.id. Instead, it will evaluate id == id as True and return all users. You need to use .filter(users.id == id) (as demoed above). I made this mistake earlier today.
– Nico Cernek
Feb 22 '19 at 23:00
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Specify sudo password for Ansible
...
For example, you might have a playbook something like this:
- hosts: all
vars_files:
- secret
tasks:
- name: Do something as sudo
service: name=nginx state=restarted
sudo: yes
Here we are including a file called secret which will contain our sudo password.
We will...
Templated check for the existence of a class member function?
... Although, I used the following for 'one' and 'two': typedef char Small; class Big{char dummy[2];} to ensure no ambiguity about platform dependent variable size.
– user23167
Nov 2 '08 at 21:40
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Using awk to print all columns from the nth to the last
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will print all but very first column:
awk '{$1=""; print $0}' somefile
will print all but two first columns:
awk '{$1=$2=""; print $0}' somefile
share
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If string is empty then return some default value
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ActiveSupport adds a presence method to all objects that returns its receiver if present? (the opposite of blank?), and nil otherwise.
Example:
host = config[:host].presence || 'localhost'
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Adding a directory to $LOAD_PATH (Ruby)
...so long as the memory usage is the same for each, which I assume it essentially is.
– boulder_ruby
Oct 12 '12 at 1:47
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How can jQuery deferred be used?
... // or may not have been retrieved using an
// XHR request.
});
Basically, if the value has already been requested once before it's returned immediately from the cache. Otherwise, an AJAX request fetches the data and adds it to the cache. The $.when/.then doesn't care about any of this; all ...
Checking if array is multidimensional or not?
...will recursively count the array. This is particularly useful for counting all the elements of a multidimensional array. count() does not detect infinite recursion.
However this method does not detect array(array()).
share...
Time complexity of Sieve of Eratosthenes algorithm
...oose upper-bound is n(1+1/2+1/3+1/4+1/5+1/6+…1/n) (sum of reciprocals of all numbers up to n), which is O(n log n): see Harmonic number. A more proper upper-bound is n(1/2 + 1/3 + 1/5 + 1/7 + …), that is sum of reciprocals of primes up to n, which is O(n log log n). (See here or here.)
The "find...
MySql Table Insert if not exist otherwise update
...since it's the unique key, so it should not change. You do need to include all of the other columns from your table. You can use the VALUES() function to make sure the proper values are used when updating the other columns.
Here is your update re-written using the proper INSERT ... ON DUPLICATE KEY...