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SQL (Structured Query Language)
SQL (Structured Query Language) is a database computer language designed for managing data in relational database management systems (RDBMS), and originally based upon Relational Algebra. Its scope includes data query and update, schema creation and modification, and data access control. SQL was one of the first languages for Edgar F. Codd's relational model in his influential 1970 paper, "A Relational Model of Data for Large Shared Data Banks" and became the most widely used language for relational databases.

SQL Language elements
The SQL language is sub-divided into several language elements, including:
  1. Clauses, which are in some cases optional, constituent components of statements and queries.
  2. Expressions which can produce either scalar values or tables consisting of columns and rows of data.
  3. Predicates which specify conditions that can be evaluated to SQL three-valued logic (3VL) Boolean truth values and which are used to limit the effects of statements and queries, or to change program flow.
  4. Queries which retrieve data based on specific criteria.
  5. Statements which may have a persistent effect on schemas and data, or which may control transactions, program flow, connections, sessions, or diagnostics.
  6. SQL statements also include the semicolon (";") statement terminator. Though not required on every platform, it is defined as a standard part of the SQL grammar.
  7. Insignificant whitespace is generally ignored in SQL statements and queries, making it easier to format SQL code for readability.