SQL - Structured Query Language

Author: Chris Connolly

Definition

SQL stands for structured query language - it is the optimized data programming language required to handle database functions and operations.

Description

Structured Query Language (SQL) is a language used to view or change data in databases.
SQL can be used to perform tasks such as update data on a database, or retrieve data from a database. Some common relational database management systems that use SQL are: Oracle, Sybase, Microsoft SQL Server, Access, Ingres, etc. Although most database systems use SQL, most of them also have their own additional proprietary extensions that are usually only used on their system.


Explanation and application


The sentences or programming used in this language are called SQL Queries. If we want to add data to the database in a computer, or to remove data from the database, or to just view the data in the database, we can use SQL Queries. Such as "Select", "Insert", "Update", "Delete", "Create", and "Drop". These can be used to accomplish almost everything that one needs to do with a database.

SQL Language elements:

The SQL language is based on several elements. For the convenience of SQL developers all necessary language commands in the corresponding database management systems are usually executed through a specific SQL command-line interface (CLI).

Clauses - the clauses are components of the statements and the queries
Expressions - the expressions can produce scalar values or tables, which consist of columns and rows of data
Predicates - they specify conditions, which are used to limit the effects of the statements and the queries, or to change the program flow
Queries - a query will retrieve data, based on a given criteria
Statements - with the statements one can control transactions, program flow, connections, sessions, or diagnostics. In database systems the SQL statements are used for sending queries from a client program to a server where the databases are stored. In response, the server processes the SQL statements and returns replies to the client program. This allows users to execute a wide range of amazingly fast data manipulation operations from simple data inputs to complicated queries.

In terms of supermarket usage, this is how the creation of design of the SQL database would have been created;

Things that will be in the tables:

Products (name, price, minimum quantity, current quantity…)
Customers (name, phone, address…)
Suppliers (name, phone, address…)

Bills:-
Cost of items (from suppliers)
Selling - I.E invoices and sales history (to customers)
Store - I.E electricity, gas etc. (there is only one store in which we can keep some stuff then bring them to the supermarket when needed)


Links to Social and Ethical Issues


Please note that not all issues need to be addressed. Please add the URL or source of any examples to support your suggestion. It may be helpful to RANK the issues in the THIRD column.

Social & Ethical Issue
Examples that specifically link to the concept and/or definition in the Case Study
Ranking
1.1 Reliability and integrity


1.2 Security


1.3 Privacy and anonymity


1.4 Intellectual property


1.5 Authenticity


1.6 The digital divide and equality of access


1.7 Surveillance


1.8 Globalization and cultural diversity


1.9 Policies


1.10 Standards and protocols


1.11 People and machines


1.12 Digital citizenship








References and resources


http://www.sqlcourse.com/intro.html
http://simple.wikipedia.org/wiki/Structured_Query_Language
http://www.muaz-othman.com/en/?p=61