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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.
Chatteris /ˈtʃætɛrɪs/ is a market town and civil parish in the Fenland district of Cambridgeshire, England, situated in The Fens between Huntingdon, March and Ely. The town is in the North East Cambridgeshire parliamentary constituency.
The parish of Chatteris is large, covering 6,099 hectares, and for much of its history was a raised island in the low-lying wetland of the Fens. Mentioned in the Domesday Book of 1086, the town has evidence of settlement from the Neolithic period.[1] After several fires in the 18th and 19th centuries, the majority of the town's housing dates from the late Victorian period onwards, with the tower of the parish church the only medieval building remaining.
Following the draining of the Fens, beginning in the 17th century and completed in the 19th century, the town's economy has been based on agriculture and related industry. Due to its proximity to Cambridge, Huntingdon and Peterborough, the town has emerged as a commuter town. The town had a population of 11,011 at the time of the United Kingdom Census 2021.
