Answer:
A primary key is a special relational database table column (or combination of columns) designated to uniquely identify each table record. A primary key is used as a unique identifier to quickly parse data within the table. A table cannot have more than one primary key.
Primary Key.
Candidate Key.
Alternate Key.
Super Key.
Composite Key.
Foreign Key.
Unique Key.
In the relational model of databases, a primary key is a specific choice of a minimal set of attributes that uniquely specify a tuple in a relation. Informally, a primary key is "which attributes identify a record," and in simple cases constitute a single attribute: a unique ID.
Explanation:
Common input devices include the keyboard, image scanner, and integrated video cameras. These also include the microphone, mouse, joystick controller, gamepad or joypad, webcam, digital pen, and others. Input devices are computer hardware used to control signals and provide data to a computer or an information appliance.
Answer:
False
Explanation:
No app icon on app's action bar will move the device to its home screen.It is not a valid statement.
