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The SQL language

Relational databases are often linked to Structured Query Language (SQL). SQL is a declarative programming language and is the standard relational database language. The ANSI and the International Organization for Standardization (ISO) published the SQL standard for the first time in 1986, followed by many versions such as SQL:1999, SQL:2003, SQL:2006, SQL:2008, SQL:2011, and SQL:2016.

The SQL language has several parts:

  • Data definition language (DDL): It defines and amends the relational structure
  • Data manipulation language (DML): It retrieves and extracts information from the relations
  • Data control language (DCL): It controls the access rights to relations
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