SQL stands for Structured Query Language. It is a standard language used to access, manage and manipulate data stored in relational database systems.
SQL was developed by IBM researchers in the 1970s. Although it is often described as a programming language, it is more accurately classified as a domain-specific language designed primarily for working with databases rather than as a general-purpose programming language.
SQL is mainly used to interact with relational databases and database management systems. It supports operations such as defining data structures, retrieving and analysing information, modifying records and controlling access to data.
Through SQL, users can create, delete and modify database tables, run queries, process results and manage stored information. Database management systems execute SQL commands and return the requested results.
SQL can also be used to monitor and optimise database performance. Its relatively simple syntax and ability to integrate with different programming languages make it a widely used tool among data analysts, developers and database administrators.
SQL is supported by many database management systems, including MySQL, Microsoft SQL Server, Oracle Database, IBM Db2, PostgreSQL, Sybase, IBM Informix, Progress, Firebird and Microsoft Access.
As one of the foundations of database management, SQL works with database servers that process queries and return the relevant results. Although each database system may have its own features and extensions, most systems support standard SQL commands.
The primary purpose of SQL is to organise, model and manage data effectively. Depending on the requirements of the application, SQL can be used for a wide range of operations, from retrieving individual records to processing large datasets.
SQL is commonly used to control information stored in databases and retrieve specific data when needed. Although its syntax is relatively straightforward, it is a powerful language capable of handling large volumes of structured data.
Some of the most commonly used SQL commands include:
- INSERT, which adds new records to a database table.
- SELECT, which retrieves data from one or more tables.
- UPDATE, which modifies existing records.
- DELETE, which removes records from a table.
These commands form the basis of many database operations carried out through SQL.
