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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.
Lincolnshire (abbreviated Lincs.) is a county in the East Midlands of England, with a long coastline on the North Sea to the east. It borders Norfolk to the south-east, Cambridgeshire to the south, Rutland to the south-west, Leicestershire and Nottinghamshire to the west, South Yorkshire to the north-west, and the East Riding of Yorkshire to the north. It also borders Northamptonshire in the south for just 20 yards (19 m), England's shortest county boundary.[2] The county town is the city of Lincoln, where the county council has its headquarters.
The ceremonial county of Lincolnshire consists of the non-metropolitan county of Lincolnshire and the area covered by the unitary authorities of North Lincolnshire and North East Lincolnshire. Part of the ceremonial county is in the Yorkshire and the Humber region of England, and most is in the East Midlands region. The county is the second-largest of the English ceremonial counties and one that is predominantly agricultural in land use. The county is fourth-largest of the two-tier counties, as the unitary authorities of North Lincolnshire and North East Lincolnshire are not included.
The county has several geographical sub-regions, including the rolling chalk hills of the Lincolnshire Wolds. In the south-east are the Lincolnshire Fens (south-east Lincolnshire), the Carrs (similar to the Fens but in north Lincolnshire), the industrial Humber Estuary and North Sea coast around Grimsby and Scunthorpe, and in the south-west of the county, the Kesteven Uplands, rolling limestone hills in the district of South Kesteven.
