Tutorial by Examples: d

Deleting documents from a collection in mongoose is done in the following manner. Auto.remove({_id:123}, function(err, result){ if (err) return console.error(err); console.log(result); // this will specify the mongo default delete result. });

You can use plugman command to install/uninstall custom cordova plugins. To install plugman npm install -g plugman Install plugin command syntax: plugman <install|uninstall> --platform <ios|android|blackberry10|wp8> --project <directory> --plugin <name|url|path> Exa...

The names of modules follow the filesystem's hierarchical structure. With the following file layout: Foo/ ├── Baz/ │ └── Quux.hs └── Bar.hs Foo.hs Bar.hs the module headers would look like this: -- file Foo.hs module Foo where -- file Bar.hs module Bar where -- file Foo/Bar.hs m...

systemd provides a modern implementation of cron. To execute a script periodical a service and a timer file ist needed. The service and timer files should be placed in /etc/systemd/{system,user}. The service file: [Unit] Description=my script or programm does the very best and this is the descri...

Below is an example of Gstreamer pipeline embedded in a simple gtk window. When run, a small window should appear like this: import gi gi.require_version('Gtk', '3.0') gi.require_version('Gst', '1.0') from gi.repository import Gtk, Gst Gst.init(None) Gst.init_check(None) class GstWidg...

update <SCHEMA_NAME>.<TABLE_NAME_1> AS A SET <COLUMN_1> = True FROM <SCHEMA_NAME>.<TABLE_NAME_2> AS B WHERE A.<COLUMN_2> = B.<COLUMN_2> AND A.<COLUMN_3> = B.<COLUMN_3>

Monthwise difference between two dates(timestamp) select ( (DATE_PART('year', AgeonDate) - DATE_PART('year', tmpdate)) * 12 + (DATE_PART('month', AgeonDate) - DATE_PART('month', tmpdate)) ) from dbo."Table1" Yearwise difference between two dates...

To check the list of loaded packages search() OR (.packages())

A frequent reason why your read operation may not work is because your security rules reject the operation, for example because you're not authenticated (by default a database can only be accessed by an authenticated user). You can see these security rule violations in the Console output. But it's ...

Model With EF Core, data access is performed using a model. A model is made up of entity classes and a derived context that represents a session with the database, allowing you to query and save data. You can generate a model from an existing database, hand code a model to match your database, or ...

The following table compares the features available(1) in EF Core and EF6.x. It is intended to give a high level comparison and does not list every feature, or attempt to give details on possible differences between how the same feature works. Creating a ModelEF6.xEF Core 1.0.0Basic modelling (cla...

<?php echo get_field('my_field_name', 123); ?> This will echo the value of "my_field_name" from the post with 123 as its ID.

<?php echo get_field('my_field_name', 'option'); ?> This will echo the value of "my_field_name" from the options page created via ACF.

<?php if( get_field('my_field_name') ){ ?> <?php echo get_field('my_field_name'); ?> <?php }; ?> This will only show the field if content exists depending on content type (i.e., an image is uploaded to the field, text is entered, it is selected, etc.).

A typical payment flow with Stripe can be divided in two steps: Client-side, in your frontend (HTML + Javascript) code, you collect the customer's payment information using Stripe's prebuilt Checkout form or Elements form field(s). This will return a token that you then send to your server. ...

First of all we need to add MEDIA_ROOT and MEDIA_URL to our settings.py file MEDIA_ROOT = os.path.join(BASE_DIR, 'media') MEDIA_URL = '/media/' Also here you will work with ImageField, so remember in such cases install Pillow library (pip install pillow). Otherwise, you will have such error: I...

The setCustomTitle() method of AlertDialog.Builder lets you specify an arbitrary view to be used for the dialog title. One common use for this method is to build an alert dialog that has a long title. AlertDialog.Builder builder = new AlertDialog.Builder(context, Theme_Material_Light_Dialog); buil...

To define an atom, use an ordinary def, but add an atom function before it, like so: (def counter (atom 0)) This creates an atom of value 0. Atoms can be of any type: (def foo (atom "Hello")) (def bar (atom ["W" "o" "r" "l" "d"])) ...

To read an atom's value, simply put the name of the atom, with a @ before it: @counter ; => 0 A bigger example: (def number (atom 3)) (println (inc @number)) ;; This should output 4

There are two commands to change an atom, swap! and reset!. swap! is given commands, and changes the atom based on its current state. reset! changes the atom's value completely, regardless of what the original atom's value was: (swap! counter inc) ; => 1 (reset! counter 0) ; => 0 This e...