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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...
Aggregate / summarize multiple variables per group (e.g. sum, mean)
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Using the data.table package, which is fast (useful for larger datasets)
https://github.com/Rdatatable/data.table/wiki
library(data.table)
df2 <- setDT(df1)[, lapply(.SD, sum), by=.(year, month), .SDcols=c("x1","x2")]
setDF(df2) # con...
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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Serializing object that contains cyclic object value
... goes.
One feature that's not as well-known as JSON.stringify() is console.table(). Simply call console.table(whatever);, and it will log the variable in the console in tabular format, making it rather quite easy and convenient to peruse the variable's contents.
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How to find out the MySQL root password
... did the following:
sudo service mysql stop
sudo mysqld_safe --skip-grant-tables --skip-syslog --skip-networking
Then run mysql in a new terminal:
mysql -u root
And run the following queries to change the password:
UPDATE mysql.user SET authentication_string=PASSWORD('password') WHERE User='r...
MySQL Orderby a number, Nulls last
...sign (-) before the column name and switch the ASC to DESC:
SELECT * FROM tablename WHERE visible=1 ORDER BY -position DESC, id DESC
It is essentially the inverse of position DESC placing the NULL values last but otherwise the same as position ASC.
A good reference is here http://troels.arvin.dk...
Advantages and disadvantages of GUID / UUID database keys
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@Matt Sheppard:
Say you have a table of customers. Surely you don't want a customer to exist in the table more than once, or lots of confusion will happen throughout your sales and logistics departments (especially if the multiple rows about the customer c...
Can I force a UITableView to hide the separator between empty cells? [duplicate]
When using a plain-style UITableView with a large enough number of cells that the UITableView cannot display them all without scrolling, no separators appear in the empty space below the cells. If I have only a few cells the empty space below them includes separators.
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Use didSelectRowAtIndexPath or prepareForSegue method for UITableView?
I'm using storyboards and I have a UITableView. I have a segue setup that pushes from my table to the detail VC. But which method should I use to handle this? I'll have to pass a couple objects to the detail view. But do I use didSelectRowAtIndex or -(void)prepareForSegue:(UIStoryboardSegue *...
Why the switch statement cannot be applied on strings?
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Additionally, C/C++ switch statements are typically generated as branch tables. It's not nearly as easy to generate a branch table for a string style switch.
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