SQL Standards and Versions

SQL (Structured Query Language) has evolved over time through various standards and versions, improving its functionality and compatibility across database management systems. These standards are set by ANSI (American National Standards Institute) and ISO (International Organization for Standardization) to ensure consistency in SQL implementations.

Key SQL Standards and Their Features

Below is an overview of major SQL standards and their highlights:

1. SQL-86

The first SQL standard was introduced in 1986. It provided the foundational structure for SQL, focusing on basic querying and data manipulation.

      CREATE TABLE SQL_Standards (
          Version VARCHAR(20) PRIMARY KEY,
          Year INT,
          Features TEXT
      );

      INSERT INTO SQL_Standards (Version, Year, Features)
      VALUES 
      ('SQL-86', 1986, 'Introduced basic SQL syntax for querying and data manipulation');
    

2. SQL-89

This version, also called SQL1, included minor updates and refinements to the initial standard.

      INSERT INTO SQL_Standards (Version, Year, Features)
      VALUES 
      ('SQL-89', 1989, 'Minor updates and corrections to SQL-86');
    

3. SQL-92

SQL-92, or SQL2, was a major update that introduced new data types, more robust JOIN operations, and integrity constraints.

      INSERT INTO SQL_Standards (Version, Year, Features)
      VALUES 
      ('SQL-92', 1992, 'Introduced new data types, JOIN types, and integrity constraints');
    

4. SQL:1999

This version added object-oriented features, recursive queries, and support for procedural extensions.

      INSERT INTO SQL_Standards (Version, Year, Features)
      VALUES 
      ('SQL:1999', 1999, 'Added recursive queries, triggers, and procedural extensions');
    

5. SQL:2003

SQL:2003 introduced XML data types, window functions, and enhanced the MERGE statement.

      INSERT INTO SQL_Standards (Version, Year, Features)
      VALUES 
      ('SQL:2003', 2003, 'Introduced XML data types, window functions, and MERGE');
    

6. SQL:2011

This version added temporal database features, enabling better handling of time-based data.

      INSERT INTO SQL_Standards (Version, Year, Features)
      VALUES 
      ('SQL:2011', 2011, 'Added support for temporal data and time-based queries');
    

7. SQL:2016

SQL:2016 focused on integrating JSON support, ensuring better compatibility with modern applications.

      INSERT INTO SQL_Standards (Version, Year, Features)
      VALUES 
      ('SQL:2016', 2016, 'Introduced JSON support for modern data formats');
    

8. SQL:2019

The most recent update, SQL:2019, improved support for big data and analytics by introducing polymorphic table functions.

      INSERT INTO SQL_Standards (Version, Year, Features)
      VALUES 
      ('SQL:2019', 2019, 'Enhanced support for big data and analytics with polymorphic table functions');
    

Querying the History of SQL Standards

To view all SQL standards and their features, use the following SQL query:

      SELECT * FROM SQL_Standards;
    

Conclusion

The evolution of SQL standards reflects the changing demands of database management systems, ensuring SQL remains a powerful and versatile language. Familiarity with these standards is essential for understanding SQL's capabilities and its applications across various domains.