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How to install mongoDB on windows?
...st imagine an SQL server or Oracle Db with entirely different rows in same table? Is it possible in our relational DB table? This is how mongo works. I will show you how we can do that…
First I will show you how the data will look in a relational DB.
For example consider an Employee table and a S...
brew install mysql on macOS
... like there is something wrong with the set up instructions or the initial tables that are being created. This is how I got mysqld running on my machine.
If the mysqld server is already running on your Mac, stop it first with:
launchctl unload -w ~/Library/LaunchAgents/com.mysql.mysqld.plist
Star...
Linear Regression and group by in R
...factor are your variables. Please keep in mind that Your.df must be a data.table class
– FraNut
Nov 17 '15 at 9:33
...
Why switch is faster than if
...h switch the JVM loads the value to compare and iterates through the value table to find a match, which is faster in most cases.
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how to generate migration to make references polymorphic
I have a Products table and want to add a column:
4 Answers
4
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ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock'
...nit.d/mysqld stop
Start MySQL in safe mode
sudo mysqld_safe --skip-grant-tables &
Log into MySQL using root
mysql -uroot
Select the MySQL database to use
use mysql;
Reset the password
-- MySQL version < 5.7
update user set password=PASSWORD("mynewpassword") where User='root';
-- MySQ...
Fast permutation -> number -> permutation mapping algorithms
... brought down to n*log(n), see section 10.1.1
("The Lehmer code (inversion table)", p.232ff) of the fxtbook:
http://www.jjj.de/fxt/#fxtbook
skip to section 10.1.1.1 ("Computation with large arrays" p.235) for the fast method.
The (GPLed, C++) code is on the same web page.
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Rails 4 LIKE query - ActiveRecord adds quotes
...
def self.search(query, page=1)
query = "%#{query}%"
name_match = arel_table[:name].matches(query)
postal_match = arel_table[:postal_code].matches(query)
where(name_match.or(postal_match)).page(page).per_page(5)
end
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How do I update if exists, insert if not (AKA “upsert” or “merge”) in MySQL?
... @blub: If you create a unique key on geb and topic it will work (ALTER TABLE table ADD UNIQUE geb_by_topic (geb, topic)).
– chaos
Aug 2 '09 at 13:43
1
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How do I connect to a MySQL Database in Python?
... = db.cursor()
# Use all the SQL you like
cur.execute("SELECT * FROM YOUR_TABLE_NAME")
# print all the first cell of all the rows
for row in cur.fetchall():
print row[0]
db.close()
Of course, there are thousand of possibilities and options; this is a very basic example. You will have to loo...