Tutorial by Examples: ti

PHP lacks a build-in function to encrypt and decrypt large files. openssl_encrypt can be used to encrypt strings, but loading a huge file into memory is a bad idea. So we have to write a userland function doing that. This example uses the symmetric AES-128-CBC algorithm to encrypt smaller chunks of...

Suppose you have two views ViewA and ViewB Instance of ViewB is created inside ViewA, so ViewA can send message to ViewB's instance, but for the reverse to happen we need to implement delegation (so that using delegate ViewB's instance could send message to ViewA) Follow these steps to implement t...

Move to the SQL Server Management Studio menu bar (ALT) Activate the menu for a tool component (ALT+ HYPHEN) Display the context menu (SHIFT+F) Display the New File dialog box to create a file (CTRL+N) Display the Open Project dialog box to open an existing project (CTRL+SHIFT+0) Display the ...

Let say you want to build your API to comply jsonapi.org specification and the result should look like: { "article": { "id": "305", "type": "articles", "attributes": { "title": "Asking Alexandria&q...

In Vim, your configuration file is ~/.vimrc, with further configuration files in ~/.vim. In Neovim, configuration files are located in ~/.config/nvim. There is also no ~/.nvimrc file. Instead, use ~/.config/nvim/init.vim. You can import your Vim configuration directly into Neovim using this Unix c...

This fetches the value of NOW() in local time, in India Standard Time, and then again in UTC. SELECT NOW(); SET time_zone='Asia/Kolkata'; SELECT NOW(); SET time_zone='UTC'; SELECT NOW();

If you have a stored DATE or DATETIME (in a column somewhere) it was stored with respect to some time zone, but in MySQL the time zone is not stored with the value. So, if you want to convert it to another time zone, you can, but you must know the original time zone. Using CONVERT_TZ() does the con...

This is really easy. All TIMESTAMP values are stored in universal time, and always converted to the present time_zone setting whenever they are rendered. SET SESSION time_zone='America/Los_Angeles'; SELECT timestamp_sold FROM sales WHERE state_sold = 'CA' Why is this? TIMESTAMP values are...

Each server has a default global time_zone setting, configured by the owner of the server machine. You can find out the current time zone setting this way: SELECT @@time_zone Unfortunately, that usually yields the value SYSTEM, meaning the MySQL time is governed by the server OS's time zone sett...

To get a list of possible time_zone values in your MySQL server instance, use this command. SELECT mysql.time_zone_name.name Ordinarily, this shows the ZoneInfo list of time zones maintained by Paul Eggert at the Internet Assigned Numbers Authority. Worldwide there are appproximately 600 time z...

SELECT NOW(3) does the trick.

Javascript timestamps are based on the venerable UNIX time_t data type, and show the number of milliseconds since 1970-01-01 00:00:00 UTC. This expression gets the current time as a Javascript timestamp integer. (It does so correctly regardless of the current time_zone setting.) ROUND(UNIX_TIMEST...

CREATE TABLE times ( dt DATETIME(3), ts TIMESTAMP(3) ); makes a table with millisecond-precision date / time fields. INSERT INTO times VALUES (NOW(3), NOW(3)); inserts a row containing NOW() values with millisecond precision into the table. INSERT INTO times VALUES ('2015-01...

%f is the fractional precision format specifier for the DATE_FORMAT() function. SELECT DATE_FORMAT(NOW(3), '%Y-%m-%d %H:%i:%s.%f') displays a value like 2016-11-19 09:52:53.248000 with fractional microseconds. Because we used NOW(3), the final three digits in the fraction are 0.

If you have a Javascript timestamp value, for example 1478960868932, you can convert that to a MySQL fractional time value like this: FROM_UNIXTIME(1478960868932 * 0.001) It's simple to use that kind of expression to store your Javascript timestamp into a MySQL table. Do this: INSERT INTO table...

authenticate_with_http_token do |token, options| @user = User.find_by(auth_token: token) end You can test this endpoint with curl by making a request like curl -IH "Authorization: Token token=my-token" http://localhost:3000

RelativePanel has been introduced in Windows 10 and is used mainly to support adaptive layouts, where the child elements of the panel are laid out differently depending on available space. RelativePanel is typically used with visual states, which are used to switch the layout configuration, adaptin...

get_option function is used to retrieve a value from from options table based on option name. You can use the following code to get email address of a WordPress site administrator. <?php echo get_option('admin_email'); ?> get_option() has an optional 2nd argument, which allows you to set ...

Given an m times n matrix A with n larger than m. The singular value decomposition [U,S,V] = svd(A); computes the matrices U,S,V. The matrix U consists of the left singular eigenvectors which are the eigenvectors of A*A.' while V consists of the right singular eigenvalues which are the eigenvec...

Template Generic Syntax template<typename T> void f(ParamType param); f(expr); Case 1: ParamType is a Reference or Pointer, but not a Universal or Forward Reference. In this case type deduction works this way. The compiler ignores the reference part if it exists in expr. The compiler t...