SQL definition?

What is SQL? Structured query language (SQL) is a programming language for storing and processing information in a relational database. A relational database stores information in tabular form, with rows and columns representing different data attributes and the various relationships between the data values. You can use SQL statements to store, update, remove, search, and retrieve information from the database. You can also use SQL to maintain and optimize database performance. Why is SQL important? Structured query language (SQL) is a popular query language that is frequently used in all types of applications. Data analysts and developers learn and use SQL because it integrates well with different programming languages. For example, they can embed SQL queries with the Java programming language to build high-performing data processing applications with major SQL database systems such as Oracle or MS SQL Server. SQL is also fairly easy to learn as it uses common English keywords in its statements History of SQL SQL was invented in the 1970s based on the relational data model. It was initially known as the structured English query language (SEQUEL). The term was later shortened to SQL. Oracle, formerly known as Relational Software, became the first vendor to offer a commercial SQL relational database management system. What are the components of a SQL system? Relational database management systems use structured query language (SQL) to store and manage data. The system stores multiple database tables that relate to each other. MS SQL Server, MySQL, or MS Access are examples of relational database management systems. The following are the components of such a system. SQL table A SQL table is the basic element of a relational database. The SQL database table consists of rows and columns. Database engineers create relationships between multiple database tables to optimize data storage space. For example, the database engineer creates a SQL table for products in a store: Product ID Product Name Color ID 0001 Mattress Color 1 0002 Pillow Color 2 Then the database engineer links the product table to the color table with the Color ID: Color ID Color Name Color 1 Blue Color 2 Red VALUES(‘A’,’499’); Stored procedures Stored procedures are a collection of one or more SQL statements stored in the relational database. Software developers use stored procedures to improve efficiency and performance. For example, they can create a stored procedure for updating sales tables instead of writing the same SQL statement in different applications. How does SQL work? Structured query language (SQL) implementation involves a server machine that processes the database queries and returns the results. The SQL process goes through several software components, including the following. Parser The parser starts by tokenizing, or replacing, some of the words in the SQL statement with special symbols. It then checks the statement for the following: Correctness The parser verifies that the SQL statement conforms to SQL semantics, or rules, that ensure the correctness of the query statement. For example, the parser checks if the SQL command ends with a semi-colon. If the semi-colon is missing, the parser returns an error. Authorization The parser also validates that the user running the query has the necessary authorization to manipulate the respective data. For example, only admin users might have the right to delete data. Relational engine The relational engine, or query processor, creates a plan for retrieving, writing, or updating the corresponding data in the most effective manner. For example, it checks for similar queries, reuses previous data manipulation methods, or creates a new one. It writes the plan in an intermediate-level representation of the SQL statement called byte code. Relational databases use byte code to efficiently perform database searches and modifications. Storage engine The storage engine, or database engine, is the software component that processes the byte code and runs the intended SQL statement. It reads and stores the data in the database files on physical disk storage. Upon completion, the storage engine returns the result to the requesting application.