Tutorial by Examples: delete

When you inherit from a class with a property, you can provide a new implementation for one or more of the property getter, setter or deleter functions, by referencing the property object on the parent class: class BaseClass(object): @property def foo(self): return some_calculate...

The delete operator deletes a property from an object. Syntax: delete object.property delete object['property'] Returns: If deletion is successful, or the property did not exist: true If the property to be deleted is an own non-configurable property (can't be deleted): false in non...

To destroy, delete, or unset an array: unset array To destroy, delete, or unset a single array element: unset array[10]

Given a file file.txt with the following content: line 1 line 2 line 3 You can delete a line from file content with the d command. The pattern to match is surrounded with default / delimiter and the d command follows the pattern: sed '/line 2/d' file.txt The above command will output: l...

Shortest match: $ a='I am a string' $ echo "${a#*a}" m a string Longest match: $ echo "${a##*a}" string

Shortest match: $ a='I am a string' $ echo "${a%a*}" I am Longest match: $ echo "${a%%a*}" I

SP.SOD.executeOrDelayUntilScriptLoaded( function(){ deleteItem(1); }, "sp.js"); function deleteItem(id){ var clientContext = new SP.ClientContext(); var list = clientContext.get_web().get_lists().getByTitle("List Title"); var item = list.getItemById(id); it...

#!/bin/bash NO_SNAPSHOTS="No snapshots have been taken yet" SNAPSHOT_OUTPUT=$(vagrant snapshot list | grep "${NO_SNAPSHOTS}") if [ -z "${SNAPSHOT_OUTPUT}" ]; then echo "Found some snapshots, going to remove them" for SNAPSHOT in $(vagrant snap...

MySQL's DELETE statement can use the JOIN construct, allowing also to specify which tables to delete from. This is useful to avoid nested queries. Given the schema: create table people ( id int primary key, name varchar(100) not null, gender char(1) not null ); insert people (id,na...

when the object is deleted, delete all the objects in the association.

when the object is deleted, delete all the objects in the association. In addition to that, when an object is removed from the association and not associated with another object (orphaned), also delete it.

when an object is save/update/delete, check the associations and save/update/delete all the objects found. In additional to that, when an object is removed from the association and not associated with another object (orphaned), also delete it.

If you need to delete a lot of records quickly, ActiveRecord gives .delete_all method. to be called directly on a model, to delete all records in that table, or a collection. Beware though, as .delete_all does not instantiate any object hence does not provide any callback (before_* and after_destroy...

CREATE TRIGGER BooksDeleteTrigger ON MyBooksDB.Books AFTER DELETE AS INSERT INTO BooksRecycleBin SELECT * FROM deleted; GO

DELETE FROM `myTable` WHERE `someColumn` = 'something' The WHERE clause is optional but without it all rows are deleted.

Docker volumes are not automatically removed when a container is stopped. To remove associated volumes when you stop a container: docker rm -v <container id or name> If the -v flag is not specified, the volume remains on-disk as a 'dangling volume'. To delete all dangling volumes: docker ...

WITH cte AS ( SELECT ProjectID, ROW_NUMBER() OVER (PARTITION BY ProjectID ORDER BY InsertDate DESC) AS rn FROM ProjectNotes ) DELETE FROM cte WHERE rn > 1;

A way to use confirm() is when some UI action does some destructive changes to the page and is better accompanied by a notification and a user confirmation - like i.e. before deleting a post message: <div id="post-102"> <p>I like Confirm modals.</p> <a data-dele...

Employees table : | ID | FirstName | LastName | Gender | Salary | +------+-----------+----------+--------+--------+ | 1 | Mark | Hastings | Male | 60000 | | 1 | Mark | Hastings | Male | 60000 | | 2 | Mary | Lambeth | Female | 30000 | | 2 | Mary | Lambe...

To delete all rows from the table //get writable database SQLiteDatabase db = openHelper.getWritableDatabase(); db.delete(TABLE_NAME, null, null); db.close(); To delete all rows from the table and get the count of the deleted row in return value //get writable database SQLiteDatabase db =...