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SQL
SQL Meaning
SQL (Structured Query Language)is a specialized programming language designed for managing and manipulating data stored in relational databases. It allows users to perform various operations such as querying, updating, inserting, and deleting data efficiently12.
Key Principles of SQL
Declarative Language: SQL is a declarative language, meaning it specifies what data to retrieve or manipulate rather than how to perform the operation. This makes it easier to use and understand1.
Standardization: SQL became a standard of the American National Standards Institute (ANSI) in 1986 and the International Organization for Standardization (ISO) in 19872.
Components: SQL consists of several sublanguages, including Data Query Language (DQL), Data Definition Language (DDL), Data Control Language (DCL), and Data Manipulation Language (DML)1.
Common SQL Commands
SELECT: Retrieves data from a database.
INSERT: Adds new records to a database.
UPDATE: Modifies existing records.
DELETE: Removes records from a database.
CREATE: Creates new database objects like tables and views.
ALTER: Modifies existing database objects.
Example of a Simple SQL Query
SELECT*FROMCustomersWHERECustomerNameLIKE'J%'ORDER BYCustomerIDDESCLIMIT 10;
This query retrieves the top 10 customers whose names start with 'J', ordered in descending order by their customer ID3.
Uses of SQL
SQL is widely used across various industries and applications, including:
Data Retrieval: Extracting data from databases for analysis and reporting.
Data Manipulation: Adding, updating, and deleting data in databases.
Data Definition: Defining the structure and organization of data in databases.
Access Control: Managing user permissions and ensuring data security23.
Important Considerations
Interoperability: SQL implementations can vary between different database systems, leading to compatibility issues1.
Security: SQL injection is a common security vulnerability where malicious SQL code is inserted into queries to manipulate or corrupt data3.
In conclusion, SQL is a powerful and versatile language for managing relational databases, offering a wide range of functionalities for data manipulation, retrieval, and security12.
Yorkshire (/ˈjɔːrkʃər, -ʃɪər/; abbreviated Yorks), formally known as the County of York, is a historic county of Northern England and the largest in the United Kingdom.[3] Because of its great size in comparison with other English counties, functions have been undertaken over time by its subdivisions, which have also been subject to periodic reform. Throughout these changes, Yorkshire has continued to be recognised as a geographic territory and cultural region.[4] The name is familiar and well understood across the United Kingdom and is in common use in the media and the military,[5] and also features in the titles of current areas of civil administration such as North Yorkshire, South Yorkshire, West Yorkshire and the East Riding of Yorkshire.
Within the borders of the historic county of Yorkshire are large stretches of unspoiled countryside, particularly within the Yorkshire Dales, North York Moors and Peak District national parks.[6] Yorkshire has been nicknamed "God's Own Country".[4][7][8]
The emblem of Yorkshire is the White Rose of the English royal House of York, and the most commonly used flag representative of Yorkshire is the white rose on a blue field[9] which, after nearly fifty years of use, was recognised by the Flag Institute on 29 July 2008.[10] Yorkshire Day, held annually on 1 August, is a celebration of the general culture of Yorkshire, ranging from its history to its dialect.[11]
Yorkshire is covered by different Government Office Regions. Most of the county falls within Yorkshire and the Humber while the extreme northern part of the county, such as Middlesbrough, Redcar, Holwick and Startforth, falls within North East England. Small areas in the west of the county are covered by the North West England region.
