SELECT column, FROM table_name; SELECT CustomerName FROM Customers; WHERE condition; SELECT * FROM CustomersWHERE Country=’Mexico’; INSERT INTO table_name (column1, column2, column3, …)VALUES (value1, value2, value3, …); INSERT INTO Customers (CustomerName, ContactName, Address, City, PostalCode, Country)VALUES (‘Cardinal’, ‘Tom B. Erichsen’, ‘Skagen 21’, ‘Stavanger’, ‘4006’, ‘Norway’); SELECT columnFROM table_nameWHERE column LIKE patternORDER BY column ASC/DESC; (Default to ASC if not specified) SELECT * FROM Customers WHERE …
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1.2.1 Interrupts
An interrupt is a signal from a device or program to request processing from the CPU. Process scheduling is handled by the OS and decides when a process is run and for how long. It needs to respond to input devices and other system events, for example when the keyboard is pressed or the hard …
1.2.1 Virtual Memory
Paging: Paging is when main memory is divided into fixed size blocks called page-frames and programs are divided into blocks of the same size called pages. Pages are swapped between secondary storage and page-frames as necessary. Each process has its own view of pages and each memory access is made up of two parts: the …
1.3.2: Databases
A database is data that is stored in an organised, structured way. E.g: your contacts are in alphabetical order. Key Terms: Table = Made up of Rows and Columns. Field = Column Record = Row Entity = An element that is being recorded in the database. Primary Key = Unique identifier for each record. Foreign …
1.2.1: System Software
Operating Systems: The operating system is a set of software that manages all the hardware and software on a computer. It enables the user to interact with the hardware and handles input and output devices. The OS sits in between the applications you run and the hardware, using hardware drivers to communicate. When a programmer …
1.3.1: Compression, Encryption, Hashing
Compression: Compression is a process of which a computer reduces the size of a file while retaining most/all of the original information. You can compress many types of files including music and video files. This means it takes up less storage space and makes uploads and downloads faster. Streaming services such as spotify or youtube …
1.3.4: Web Technologies
HTML Tags we need to know: (Other tags will be introduced in the question.) <html> <link> <head> <title> <body> <h1> <h2> <h3> <img> <a> <div> <form> <input> <p> <li> <ol> <ul> <script> CSS Need to know In-line CSS e.g: <h1 style=”color: blue;”> and external style sheets. JavaScript (Other javascript will be explained in the question.) …
1.1.2 Types Of Processors
Differences between use of CISC and RISC processors. Complex Instruction Set Computer (CISC): This type of processor attempts to reduce the number of instructions per program, however meaning the number of cycles per instruction is increased and hardware complexity is increased as it needs to understand more complex instructions. CISC architecture is designed to decrease …
Little Man Computer Tasks
Part 1: Task 1: Task 2: Task 3: Task 4: Part 2: Task 1: Task 2: Task 3: Task 4:
1.1.1: CPUs-Structure and Function
Machine Code Instructions: When we write code in a language such as python, this is readable and understood by us humans. This is known as source code. Processors can’t understand this source code so it needs to be translated into machine code. A compiler is any program that takes source code and translates it into …
Computer Science Notes 