DELETE FROM `table_name` WHERE `field_one` = 'value_one'
This will delete all rows from the table where the contents of the field_one for that row match 'value_one'
The WHERE clause works in the same way as a select, so things like >, <, <> or LIKE can be used.
Notice: It is necessa...
DELETE FROM table_name ;
This will delete everything, all rows from the table. It is the most basic example of the syntax. It also shows that DELETE statements should really be used with extra care as they may empty a table, if the WHERE clause is omitted.
DELETE FROM `table_name` WHERE `field_one` = 'value_one' LIMIT 1
This works in the same way as the 'Delete with Where clause' example, but it will stop the deletion once the limited number of rows have been removed.
If you are limiting rows for deletion like this, be aware that it will delete th...
CommandDescription<C-w>Delete word before cursor<C-t>Indent current line with by one shiftwidth<C-d>Unindent current line with by one shiftwidth<C-f>reindent the line, (move cursor to auto indent position)<C-a>Insert previously inserted text<C-e>Insert the charact...
An unnamed namespace can be used to ensure names have internal linkage (can only be referred to by the current translation unit). Such a namespace is defined in the same way as any other namespace, but without the name:
namespace {
int foo = 42;
}
foo is only visible in the translation uni...
Privileges
The CREATE VIEW statement requires the CREATE VIEW privilege for the view, and some privilege for each column selected by the SELECT statement. For columns used elsewhere in the SELECT statement, you must have the SELECT privilege. If the OR REPLACE clause is present, you must also have ...
Statement-level parallel hints are the easiest:
SELECT /*+ PARALLEL(8) */ first_name, last_name FROM employee emp;
Object-level parallel hints give more control but are more prone to errors; developers often forget to use the alias instead of the object name, or they forget to include some objec...
4.0.3
Using a CustomTabsIntent, it is now possible to configure Chrome custom tabs in order to customize key UI components in the browser that is opened from your app.
This is a good alternative to using a WebView for some cases. It allows loading of a web page with an Intent, with the added abil...
In C#, there are two different kinds of equality: reference equality and value equality. Value equality is the commonly understood meaning of equality: it means that two objects contain the same values. For example, two integers with the value of 2 have value equality. Reference equality means that ...
There are few approaches available there:
You can subscribe for keyboard appearance events notifications and change offset manually:
//Swift 2.0+
override func viewDidLoad() {
super.viewDidLoad()
NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(YourVCClas...
Controller class names are pluralized. The reason is the controller controls multiple instances of object instance.
For Example: OrdersController would be the controller for an orders table. Rails will then look for the class definition in a file called orders_controller.rb in the /app/controllers ...
The model is named using the class naming convention of unbroken MixedCase and is always the singular of the table name.
For Example: If a table was named orders, the associated model would be named Order
For Example: If a table was named posts, the associated model would be named Post
Rails will...
Common usage of lock is a critical section.
In the following example ReserveRoom is supposed to be called from different threads. Synchronization with lock is the simplest way to prevent race condition here. Method body is surrounded with lock which ensures that two or more threads cannot execute i...
Private inheritance is useful when it is required to restrict the public interface of the class:
class A {
public:
int move();
int turn();
};
class B : private A {
public:
using A::turn;
};
B b;
b.move(); // compile error
b.turn(); // OK
This approach efficiently pr...
Predefined macros are those that the compiler defines (in contrast to those user defines in the source file). Those macros must not be re-defined or undefined by user.
The following macros are predefined by the C++ standard:
__LINE__ contains the line number of the line this macro is used on, an...
To show some content in a new window, a Stage needs to be created. After creation and initialisation show or showAndWait needs to be called on the Stage object:
// create sample content
Rectangle rect = new Rectangle(100, 100, 200, 300);
Pane root = new Pane(rect);
root.setPrefSize(500, 500);
...
If you have an existing class that you'd like to use, perform Step 2 and then skip to Step 5. (For some cases, I had to add an explicit #import <Foundation/Foundation.h to an older ObjC File)
Step 1: Add Objective-C Implementation -- .m
Add a .m file to your class, and name it CustomObje...
